Date   

Re: OZ5N PLL

Andy G4JNT
 

I am / was about to lay out a PCB for locking VCXOs to a reference, using the AD4002.    The need is for a locked clock for modern Fract-N synths that work best with a clock input a fair bit higher than 10MHz - like the ADF5355   Haven't thought yet whether to use a discrete VCXO design on the PCB or do it with packaged ones.    The exact frequency isn't important, in fact its best if it's not even an exact number of MHz.   

But if a design has already been done, even if it's auto setting capability is overkill for this purpose ...



On Thu, 7 May 2020 at 17:35, Martin Phillips G4CIO <martin@...> wrote:
That's the one. One shorts a link to make it enter "search" mode, it thinks for a while (quite a long while in my case while fiddling with the coil core) and then settles down. Next time it saves the divider settings. It should work well, mine is just slightly struggling to lock from a cold start without a little help.

Martin/

On 7/5/20 4:22 PM, Andy G4JNT wrote:
Is that the design that first measures the input frequency then selects the divider ratios needed to do the locking?   All so that users don't have tp do any programming.
If it is, I wonder why the designer didn't allow the result to be blown into EE to save the measurement every time its booted up.  Of perhaps he did now.
 
(Course , I could just look it up but feeling too lazy at the moment, G+T in hand, sitting in the garden)



On Thu, 7 May 2020 at 16:15, Martin Phillips G4CIO <martin@...> wrote:
I think you're right. It would have been better on reflection. It's running with a nice voltage on the varicap, a bit below 2 V, but seems reluctant to lock quickly without a helping finger waved near to the frequency-determining components. It does however seem to lock eventually. Testing continues...

I've still got the cut-off piece of board, so it would be fairly easy to take the PLL out of the box and put it down at operating level. If I were doing that though it might be easier just to synth 106.5 from my 10 MHz standard. Any recommendations from anybody for a suitable chip that doesn't need a microscope?

I'd not thought about sequencing: I've got an old 144 MHz rig which has been adjusted to give in a foolproof manner no more than a watt or so output, the inbuilt changeover in the tvtr seems to work happily. More thought will be needed if I fit a PA. For the moment 200 mW will suffice, the dish will be over 245 m asl with a good takeoff in most directions so I should be able to hear a few people. The Cheltenham beacon is audible on just the dish feed waved out of the window.

Martin/

On 7/5/20 10:50 AM, geoffrey pike via groups.io wrote:
Hi Martin,
Glad its behaving, but there is a lot to be said for building the 106.5 MHz osc on the pcb that came with the pll
and then place all of this in the shack and send the 106.5 MHz up to the mast head. So if the pll becomes
un locked it is beside you and not 30 feet (or ~10 metres) above you.
Anyway this is what i did in the end, converting the G2 to external LO is detailed in the drawings, just make sure
its only 0dBm going into the first multiplier.

Whilst on this subject i am making some DB6NT sequencers. You really need to be careful in the P-channel Mosfet
you used. I just picked up one and stuck it in never thought about it until i realised the resistance was 800 m Ohms.
Not  a problem you would think until you realise how much is dropped across it at 4A (this feeds the PA).
The type DB6NT uses have on resistances of 20 m Ohms, a vast difference.
Good luck
Geoff
GI0GDP




On Thursday, 7 May 2020, 10:08:56 BST, Martin Phillips G4CIO <martin@...> wrote:


It's looking good so far... I'd been struggling to get the 1 Hz flashing
light, it kept going solid! I'm letting it cool down at the moment to
see if it will restart from cold. It was a fiddle to get the PLL to
configure itself but it got there eventually. I might get it up on the
mast in a few days, I'm waiting for the postman to deliver some bits
needed to box it up.

Martin/

On 6/5/20 10:00 PM, mike G6TRM via groups.io wrote:
> Hi Martin,
> It looks like you got the right advice from Geoffrey, Just to confirm
> the led is steady state when in lock.
> I like Geoffrey had some issues but finally managed to sorted them all.
> I had 3 boards, all for DB6NT transverters. 1st one, 23cm, worked
> straight off the bat, no problems... In the 2nd case, 13cm, getting
> the correct type and value of capacitor (C13 I think) was problematic,
> getting it right took me some time.  The final problem was with a 3cm
> transverter that drifted all over the place before fitting the PLL
> board...it still wouldn't lock with the PLL board, finally cured when
> I replace the crystal...
> Hope this is some help,
>
> Regards
>
> Mike G6TRM
>
>
> ----- Original Message ----- From: "Martin Phillips G4CIO"
> <martin@...>
> To: <UKMicrowaves@groups.io>
> Sent: Wednesday, May 06, 2020 6:20 PM
> Subject: [UKMicrowaves] OZ5N PLL
>
>
>> Hi all
>>
>> A few years ago Mike G6TRM did a bulk purchase of the OZ5N PLL
>> boards. I've only just got around to installing mine in a DB6NT G2 10
>> GHz tvtr and I've just started to commission it. A few questions...
>>
>> The instructions that I printed probably at the time tell me that the
>> board is in lock when the LED flashes once per second. However,
>> looking at Steen's web site, the version changed at about the time of
>> the purchase and the later model should have a steady LED when
>> locked. I wanted to confirm that the bulk-buy was of the older
>> flashing-in-lock variety. Mine, after quite a lot of fiddling, is
>> flashing, although by tweaking the oscillator coil on the G2 board I
>> can make it go steady sometimes.
>>
>> Listening to the eighth harmonic of my FT736R on 1296 MHz, the
>> received signal is at close to the right frequency (it was quite a
>> long way out before installing the PLL) but not as stable as I'd
>> really like. My 10 MHz source (Morion MV89a) seems very stable, at
>> least small adjustments to the tuning voltage only pull the tvtr a
>> few HZ. Some of it may be wobble from the FT736R, but I don't think
>> it all is. One thing that bothers me is that tweaking the oscillator
>> coil doesn't seem to affect the control voltage(CP) going to the
>> varicap from the OZ5N board. It's sitting at 3.30 V which sounds to
>> me a bit like max chip output.
>>
>> Could anyone who has set one up successfully comment please before I
>> start fiddlng more?
>>
>> Martin/
>>
>>
>>
>>
>
>
>
>







Re: OZ5N PLL

Martin Phillips G4CIO
 

That's the one. One shorts a link to make it enter "search" mode, it thinks for a while (quite a long while in my case while fiddling with the coil core) and then settles down. Next time it saves the divider settings. It should work well, mine is just slightly struggling to lock from a cold start without a little help.

Martin/

On 7/5/20 4:22 PM, Andy G4JNT wrote:
Is that the design that first measures the input frequency then selects the divider ratios needed to do the locking?   All so that users don't have tp do any programming.
If it is, I wonder why the designer didn't allow the result to be blown into EE to save the measurement every time its booted up.  Of perhaps he did now.
 
(Course , I could just look it up but feeling too lazy at the moment, G+T in hand, sitting in the garden)



On Thu, 7 May 2020 at 16:15, Martin Phillips G4CIO <martin@...> wrote:
I think you're right. It would have been better on reflection. It's running with a nice voltage on the varicap, a bit below 2 V, but seems reluctant to lock quickly without a helping finger waved near to the frequency-determining components. It does however seem to lock eventually. Testing continues...

I've still got the cut-off piece of board, so it would be fairly easy to take the PLL out of the box and put it down at operating level. If I were doing that though it might be easier just to synth 106.5 from my 10 MHz standard. Any recommendations from anybody for a suitable chip that doesn't need a microscope?

I'd not thought about sequencing: I've got an old 144 MHz rig which has been adjusted to give in a foolproof manner no more than a watt or so output, the inbuilt changeover in the tvtr seems to work happily. More thought will be needed if I fit a PA. For the moment 200 mW will suffice, the dish will be over 245 m asl with a good takeoff in most directions so I should be able to hear a few people. The Cheltenham beacon is audible on just the dish feed waved out of the window.

Martin/

On 7/5/20 10:50 AM, geoffrey pike via groups.io wrote:
Hi Martin,
Glad its behaving, but there is a lot to be said for building the 106.5 MHz osc on the pcb that came with the pll
and then place all of this in the shack and send the 106.5 MHz up to the mast head. So if the pll becomes
un locked it is beside you and not 30 feet (or ~10 metres) above you.
Anyway this is what i did in the end, converting the G2 to external LO is detailed in the drawings, just make sure
its only 0dBm going into the first multiplier.

Whilst on this subject i am making some DB6NT sequencers. You really need to be careful in the P-channel Mosfet
you used. I just picked up one and stuck it in never thought about it until i realised the resistance was 800 m Ohms.
Not  a problem you would think until you realise how much is dropped across it at 4A (this feeds the PA).
The type DB6NT uses have on resistances of 20 m Ohms, a vast difference.
Good luck
Geoff
GI0GDP




On Thursday, 7 May 2020, 10:08:56 BST, Martin Phillips G4CIO <martin@...> wrote:


It's looking good so far... I'd been struggling to get the 1 Hz flashing
light, it kept going solid! I'm letting it cool down at the moment to
see if it will restart from cold. It was a fiddle to get the PLL to
configure itself but it got there eventually. I might get it up on the
mast in a few days, I'm waiting for the postman to deliver some bits
needed to box it up.

Martin/

On 6/5/20 10:00 PM, mike G6TRM via groups.io wrote:
> Hi Martin,
> It looks like you got the right advice from Geoffrey, Just to confirm
> the led is steady state when in lock.
> I like Geoffrey had some issues but finally managed to sorted them all.
> I had 3 boards, all for DB6NT transverters. 1st one, 23cm, worked
> straight off the bat, no problems... In the 2nd case, 13cm, getting
> the correct type and value of capacitor (C13 I think) was problematic,
> getting it right took me some time.  The final problem was with a 3cm
> transverter that drifted all over the place before fitting the PLL
> board...it still wouldn't lock with the PLL board, finally cured when
> I replace the crystal...
> Hope this is some help,
>
> Regards
>
> Mike G6TRM
>
>
> ----- Original Message ----- From: "Martin Phillips G4CIO"
> <martin@...>
> To: <UKMicrowaves@groups.io>
> Sent: Wednesday, May 06, 2020 6:20 PM
> Subject: [UKMicrowaves] OZ5N PLL
>
>
>> Hi all
>>
>> A few years ago Mike G6TRM did a bulk purchase of the OZ5N PLL
>> boards. I've only just got around to installing mine in a DB6NT G2 10
>> GHz tvtr and I've just started to commission it. A few questions...
>>
>> The instructions that I printed probably at the time tell me that the
>> board is in lock when the LED flashes once per second. However,
>> looking at Steen's web site, the version changed at about the time of
>> the purchase and the later model should have a steady LED when
>> locked. I wanted to confirm that the bulk-buy was of the older
>> flashing-in-lock variety. Mine, after quite a lot of fiddling, is
>> flashing, although by tweaking the oscillator coil on the G2 board I
>> can make it go steady sometimes.
>>
>> Listening to the eighth harmonic of my FT736R on 1296 MHz, the
>> received signal is at close to the right frequency (it was quite a
>> long way out before installing the PLL) but not as stable as I'd
>> really like. My 10 MHz source (Morion MV89a) seems very stable, at
>> least small adjustments to the tuning voltage only pull the tvtr a
>> few HZ. Some of it may be wobble from the FT736R, but I don't think
>> it all is. One thing that bothers me is that tweaking the oscillator
>> coil doesn't seem to affect the control voltage(CP) going to the
>> varicap from the OZ5N board. It's sitting at 3.30 V which sounds to
>> me a bit like max chip output.
>>
>> Could anyone who has set one up successfully comment please before I
>> start fiddlng more?
>>
>> Martin/
>>
>>
>>
>>
>
>
>
>







Re: OZ5N PLL

mike G6TRM
 


Hi Andy,
The PLL is originally triggered into a read mode where it reads the input frequency. the divide ratio is then stored in memory that is read each time power is applied.
 
Mike G6TRM

----- Original Message -----
From: Andy G4JNT
Sent: Thursday, May 07, 2020 4:22 PM
Subject: Re: [UKMicrowaves] OZ5N PLL

Is that the design that first measures the input frequency then selects the divider ratios needed to do the locking?   All so that users don't have tp do any programming.
If it is, I wonder why the designer didn't allow the result to be blown into EE to save the measurement every time its booted up.  Of perhaps he did now.
 
(Course , I could just look it up but feeling too lazy at the moment, G+T in hand, sitting in the garden)



On Thu, 7 May 2020 at 16:15, Martin Phillips G4CIO <martin@...> wrote:
I think you're right. It would have been better on reflection. It's running with a nice voltage on the varicap, a bit below 2 V, but seems reluctant to lock quickly without a helping finger waved near to the frequency-determining components. It does however seem to lock eventually. Testing continues...

I've still got the cut-off piece of board, so it would be fairly easy to take the PLL out of the box and put it down at operating level. If I were doing that though it might be easier just to synth 106.5 from my 10 MHz standard. Any recommendations from anybody for a suitable chip that doesn't need a microscope?

I'd not thought about sequencing: I've got an old 144 MHz rig which has been adjusted to give in a foolproof manner no more than a watt or so output, the inbuilt changeover in the tvtr seems to work happily. More thought will be needed if I fit a PA. For the moment 200 mW will suffice, the dish will be over 245 m asl with a good takeoff in most directions so I should be able to hear a few people. The Cheltenham beacon is audible on just the dish feed waved out of the window.

Martin/

On 7/5/20 10:50 AM, geoffrey pike via groups.io wrote:
Hi Martin,
Glad its behaving, but there is a lot to be said for building the 106.5 MHz osc on the pcb that came with the pll
and then place all of this in the shack and send the 106.5 MHz up to the mast head. So if the pll becomes
un locked it is beside you and not 30 feet (or ~10 metres) above you.
Anyway this is what i did in the end, converting the G2 to external LO is detailed in the drawings, just make sure
its only 0dBm going into the first multiplier.

Whilst on this subject i am making some DB6NT sequencers. You really need to be careful in the P-channel Mosfet
you used. I just picked up one and stuck it in never thought about it until i realised the resistance was 800 m Ohms.
Not  a problem you would think until you realise how much is dropped across it at 4A (this feeds the PA).
The type DB6NT uses have on resistances of 20 m Ohms, a vast difference.
Good luck
Geoff
GI0GDP




On Thursday, 7 May 2020, 10:08:56 BST, Martin Phillips G4CIO <martin@...> wrote:


It's looking good so far... I'd been struggling to get the 1 Hz flashing
light, it kept going solid! I'm letting it cool down at the moment to
see if it will restart from cold. It was a fiddle to get the PLL to
configure itself but it got there eventually. I might get it up on the
mast in a few days, I'm waiting for the postman to deliver some bits
needed to box it up.

Martin/

On 6/5/20 10:00 PM, mike G6TRM via groups.io wrote:
> Hi Martin,
> It looks like you got the right advice from Geoffrey, Just to confirm
> the led is steady state when in lock.
> I like Geoffrey had some issues but finally managed to sorted them all.
> I had 3 boards, all for DB6NT transverters. 1st one, 23cm, worked
> straight off the bat, no problems... In the 2nd case, 13cm, getting
> the correct type and value of capacitor (C13 I think) was problematic,
> getting it right took me some time.  The final problem was with a 3cm
> transverter that drifted all over the place before fitting the PLL
> board...it still wouldn't lock with the PLL board, finally cured when
> I replace the crystal...
> Hope this is some help,
>
> Regards
>
> Mike G6TRM
>
>
> ----- Original Message ----- From: "Martin Phillips G4CIO"
> <martin@...>
> To: <UKMicrowaves@groups.io>
> Sent: Wednesday, May 06, 2020 6:20 PM
> Subject: [UKMicrowaves] OZ5N PLL
>
>
>> Hi all
>>
>> A few years ago Mike G6TRM did a bulk purchase of the OZ5N PLL
>> boards. I've only just got around to installing mine in a DB6NT G2 10
>> GHz tvtr and I've just started to commission it. A few questions...
>>
>> The instructions that I printed probably at the time tell me that the
>> board is in lock when the LED flashes once per second. However,
>> looking at Steen's web site, the version changed at about the time of
>> the purchase and the later model should have a steady LED when
>> locked. I wanted to confirm that the bulk-buy was of the older
>> flashing-in-lock variety. Mine, after quite a lot of fiddling, is
>> flashing, although by tweaking the oscillator coil on the G2 board I
>> can make it go steady sometimes.
>>
>> Listening to the eighth harmonic of my FT736R on 1296 MHz, the
>> received signal is at close to the right frequency (it was quite a
>> long way out before installing the PLL) but not as stable as I'd
>> really like. My 10 MHz source (Morion MV89a) seems very stable, at
>> least small adjustments to the tuning voltage only pull the tvtr a
>> few HZ. Some of it may be wobble from the FT736R, but I don't think
>> it all is. One thing that bothers me is that tweaking the oscillator
>> coil doesn't seem to affect the control voltage(CP) going to the
>> varicap from the OZ5N board. It's sitting at 3.30 V which sounds to
>> me a bit like max chip output.
>>
>> Could anyone who has set one up successfully comment please before I
>> start fiddlng more?
>>
>> Martin/
>>
>>
>>
>>
>
>
>
>






Re: OZ5N PLL

Andy G4JNT
 

Is that the design that first measures the input frequency then selects the divider ratios needed to do the locking?   All so that users don't have tp do any programming.
If it is, I wonder why the designer didn't allow the result to be blown into EE to save the measurement every time its booted up.  Of perhaps he did now.
 
(Course , I could just look it up but feeling too lazy at the moment, G+T in hand, sitting in the garden)



On Thu, 7 May 2020 at 16:15, Martin Phillips G4CIO <martin@...> wrote:
I think you're right. It would have been better on reflection. It's running with a nice voltage on the varicap, a bit below 2 V, but seems reluctant to lock quickly without a helping finger waved near to the frequency-determining components. It does however seem to lock eventually. Testing continues...

I've still got the cut-off piece of board, so it would be fairly easy to take the PLL out of the box and put it down at operating level. If I were doing that though it might be easier just to synth 106.5 from my 10 MHz standard. Any recommendations from anybody for a suitable chip that doesn't need a microscope?

I'd not thought about sequencing: I've got an old 144 MHz rig which has been adjusted to give in a foolproof manner no more than a watt or so output, the inbuilt changeover in the tvtr seems to work happily. More thought will be needed if I fit a PA. For the moment 200 mW will suffice, the dish will be over 245 m asl with a good takeoff in most directions so I should be able to hear a few people. The Cheltenham beacon is audible on just the dish feed waved out of the window.

Martin/

On 7/5/20 10:50 AM, geoffrey pike via groups.io wrote:
Hi Martin,
Glad its behaving, but there is a lot to be said for building the 106.5 MHz osc on the pcb that came with the pll
and then place all of this in the shack and send the 106.5 MHz up to the mast head. So if the pll becomes
un locked it is beside you and not 30 feet (or ~10 metres) above you.
Anyway this is what i did in the end, converting the G2 to external LO is detailed in the drawings, just make sure
its only 0dBm going into the first multiplier.

Whilst on this subject i am making some DB6NT sequencers. You really need to be careful in the P-channel Mosfet
you used. I just picked up one and stuck it in never thought about it until i realised the resistance was 800 m Ohms.
Not  a problem you would think until you realise how much is dropped across it at 4A (this feeds the PA).
The type DB6NT uses have on resistances of 20 m Ohms, a vast difference.
Good luck
Geoff
GI0GDP




On Thursday, 7 May 2020, 10:08:56 BST, Martin Phillips G4CIO <martin@...> wrote:


It's looking good so far... I'd been struggling to get the 1 Hz flashing
light, it kept going solid! I'm letting it cool down at the moment to
see if it will restart from cold. It was a fiddle to get the PLL to
configure itself but it got there eventually. I might get it up on the
mast in a few days, I'm waiting for the postman to deliver some bits
needed to box it up.

Martin/

On 6/5/20 10:00 PM, mike G6TRM via groups.io wrote:
> Hi Martin,
> It looks like you got the right advice from Geoffrey, Just to confirm
> the led is steady state when in lock.
> I like Geoffrey had some issues but finally managed to sorted them all.
> I had 3 boards, all for DB6NT transverters. 1st one, 23cm, worked
> straight off the bat, no problems... In the 2nd case, 13cm, getting
> the correct type and value of capacitor (C13 I think) was problematic,
> getting it right took me some time.  The final problem was with a 3cm
> transverter that drifted all over the place before fitting the PLL
> board...it still wouldn't lock with the PLL board, finally cured when
> I replace the crystal...
> Hope this is some help,
>
> Regards
>
> Mike G6TRM
>
>
> ----- Original Message ----- From: "Martin Phillips G4CIO"
> <martin@...>
> To: <UKMicrowaves@groups.io>
> Sent: Wednesday, May 06, 2020 6:20 PM
> Subject: [UKMicrowaves] OZ5N PLL
>
>
>> Hi all
>>
>> A few years ago Mike G6TRM did a bulk purchase of the OZ5N PLL
>> boards. I've only just got around to installing mine in a DB6NT G2 10
>> GHz tvtr and I've just started to commission it. A few questions...
>>
>> The instructions that I printed probably at the time tell me that the
>> board is in lock when the LED flashes once per second. However,
>> looking at Steen's web site, the version changed at about the time of
>> the purchase and the later model should have a steady LED when
>> locked. I wanted to confirm that the bulk-buy was of the older
>> flashing-in-lock variety. Mine, after quite a lot of fiddling, is
>> flashing, although by tweaking the oscillator coil on the G2 board I
>> can make it go steady sometimes.
>>
>> Listening to the eighth harmonic of my FT736R on 1296 MHz, the
>> received signal is at close to the right frequency (it was quite a
>> long way out before installing the PLL) but not as stable as I'd
>> really like. My 10 MHz source (Morion MV89a) seems very stable, at
>> least small adjustments to the tuning voltage only pull the tvtr a
>> few HZ. Some of it may be wobble from the FT736R, but I don't think
>> it all is. One thing that bothers me is that tweaking the oscillator
>> coil doesn't seem to affect the control voltage(CP) going to the
>> varicap from the OZ5N board. It's sitting at 3.30 V which sounds to
>> me a bit like max chip output.
>>
>> Could anyone who has set one up successfully comment please before I
>> start fiddlng more?
>>
>> Martin/
>>
>>
>>
>>
>
>
>
>






Re: OZ5N PLL

Martin Phillips G4CIO
 

I think you're right. It would have been better on reflection. It's running with a nice voltage on the varicap, a bit below 2 V, but seems reluctant to lock quickly without a helping finger waved near to the frequency-determining components. It does however seem to lock eventually. Testing continues...

I've still got the cut-off piece of board, so it would be fairly easy to take the PLL out of the box and put it down at operating level. If I were doing that though it might be easier just to synth 106.5 from my 10 MHz standard. Any recommendations from anybody for a suitable chip that doesn't need a microscope?

I'd not thought about sequencing: I've got an old 144 MHz rig which has been adjusted to give in a foolproof manner no more than a watt or so output, the inbuilt changeover in the tvtr seems to work happily. More thought will be needed if I fit a PA. For the moment 200 mW will suffice, the dish will be over 245 m asl with a good takeoff in most directions so I should be able to hear a few people. The Cheltenham beacon is audible on just the dish feed waved out of the window.

Martin/

On 7/5/20 10:50 AM, geoffrey pike via groups.io wrote:
Hi Martin,
Glad its behaving, but there is a lot to be said for building the 106.5 MHz osc on the pcb that came with the pll
and then place all of this in the shack and send the 106.5 MHz up to the mast head. So if the pll becomes
un locked it is beside you and not 30 feet (or ~10 metres) above you.
Anyway this is what i did in the end, converting the G2 to external LO is detailed in the drawings, just make sure
its only 0dBm going into the first multiplier.

Whilst on this subject i am making some DB6NT sequencers. You really need to be careful in the P-channel Mosfet
you used. I just picked up one and stuck it in never thought about it until i realised the resistance was 800 m Ohms.
Not  a problem you would think until you realise how much is dropped across it at 4A (this feeds the PA).
The type DB6NT uses have on resistances of 20 m Ohms, a vast difference.
Good luck
Geoff
GI0GDP




On Thursday, 7 May 2020, 10:08:56 BST, Martin Phillips G4CIO <martin@...> wrote:


It's looking good so far... I'd been struggling to get the 1 Hz flashing
light, it kept going solid! I'm letting it cool down at the moment to
see if it will restart from cold. It was a fiddle to get the PLL to
configure itself but it got there eventually. I might get it up on the
mast in a few days, I'm waiting for the postman to deliver some bits
needed to box it up.

Martin/

On 6/5/20 10:00 PM, mike G6TRM via groups.io wrote:
> Hi Martin,
> It looks like you got the right advice from Geoffrey, Just to confirm
> the led is steady state when in lock.
> I like Geoffrey had some issues but finally managed to sorted them all.
> I had 3 boards, all for DB6NT transverters. 1st one, 23cm, worked
> straight off the bat, no problems... In the 2nd case, 13cm, getting
> the correct type and value of capacitor (C13 I think) was problematic,
> getting it right took me some time.  The final problem was with a 3cm
> transverter that drifted all over the place before fitting the PLL
> board...it still wouldn't lock with the PLL board, finally cured when
> I replace the crystal...
> Hope this is some help,
>
> Regards
>
> Mike G6TRM
>
>
> ----- Original Message ----- From: "Martin Phillips G4CIO"
> <martin@...>
> To: <UKMicrowaves@groups.io>
> Sent: Wednesday, May 06, 2020 6:20 PM
> Subject: [UKMicrowaves] OZ5N PLL
>
>
>> Hi all
>>
>> A few years ago Mike G6TRM did a bulk purchase of the OZ5N PLL
>> boards. I've only just got around to installing mine in a DB6NT G2 10
>> GHz tvtr and I've just started to commission it. A few questions...
>>
>> The instructions that I printed probably at the time tell me that the
>> board is in lock when the LED flashes once per second. However,
>> looking at Steen's web site, the version changed at about the time of
>> the purchase and the later model should have a steady LED when
>> locked. I wanted to confirm that the bulk-buy was of the older
>> flashing-in-lock variety. Mine, after quite a lot of fiddling, is
>> flashing, although by tweaking the oscillator coil on the G2 board I
>> can make it go steady sometimes.
>>
>> Listening to the eighth harmonic of my FT736R on 1296 MHz, the
>> received signal is at close to the right frequency (it was quite a
>> long way out before installing the PLL) but not as stable as I'd
>> really like. My 10 MHz source (Morion MV89a) seems very stable, at
>> least small adjustments to the tuning voltage only pull the tvtr a
>> few HZ. Some of it may be wobble from the FT736R, but I don't think
>> it all is. One thing that bothers me is that tweaking the oscillator
>> coil doesn't seem to affect the control voltage(CP) going to the
>> varicap from the OZ5N board. It's sitting at 3.30 V which sounds to
>> me a bit like max chip output.
>>
>> Could anyone who has set one up successfully comment please before I
>> start fiddlng more?
>>
>> Martin/
>>
>>
>>
>>
>
>
>
>






Re: Target Image suppression for 23cms

David Bowman <g0mrf@...>
 

Hello Conrad.

That 1300MHz filter looks to be the same size / layout as the one from Murata I'm using on 2.4GHz.  (filter ahead of Gali5 + Qorvo TQP7M9101 )
Works very well and is quite easy to solder.  We have the 1267MHz version in space, so reliable too.

Didn't know 1300MHz was available. - Thank you

73  David

Assembly5.jpg



-----Original Message-----
From: Conrad, PA5Y <g0ruz@...>
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Sent: Wed, 6 May 2020 21:13
Subject: Re: [UKMicrowaves] Target Image suppression for 23cms

Thanks Andy.
 
The LNA is -3dB BW is 120MHz centred on 1296. Of course this means that the image frequency is barely attenuated. The LNA is definitely not saturating.
 
I have a nice saw filter and well as a good interdigital filter although the interdigital filter is more suitable for
 
The saw filter is here:
 
 
I’m waiting for an eval board for the SAW filter. I think that I should manage as much as 80dB image suppression definitely >70dB. It depends how good the eval board is for the SAW filter. I have 34dB gain in the LNA, 10dB cable loss 5dB loss in both filters and a 0.7dB noise figure in the transverter. AppCAD suggests that this is OK. The IIP3 of the LNA is around 4dBm. System IIP3 is around 2dB degraded by the transverter and a little excess gain. I am going to try and use a 28MHz IF for convenience but I can change this to 144 MHz if necessary. At 28 MHz the transverter images at 1240 and 1352 MHz are only 34dB down hence my concern, this is not enough.
 
I will look at the spectrum coming out of the LNA at the weekend and see how big the signals are from the cell mast 2.,5km away, my HP-8562A has died so I will have to use my E4406A in 10MHz segments. Its not a quick job! I can certainly hear that mast with the TS2000, I think that the transverter and K3S will be a step up from that.
 
Am I forgetting anything obvious?
 
73
 
Conrad PA5Y
 
 
 
 
From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Andy G4JNT via groups.io
Sent: 06 May 2020 16:41
To: UK Microwaves groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Target Image suppression for 23cms
 
Make sure 2.16GJHz is blocked.    Some 3G base stations sit here and get into the transverter as  2.LO - RF = 144MHz
I encountered this on on an SG Labs configured for dual port where the printed filter is not in-circuit on Rx
 
 
 
Andy
 
 
 
On Wed, 6 May 2020 at 15:38, Conrad, PA5Y <g0ruz@...> wrote:
Hello for a transverter on 23cms in today's RF environment what is considered to be good target for image suppression? I know that it depends where the image falls but lets consider the common IF frequencies of 28, 144 and 432 MHz.
 
73
 
Conrad PA5Y


Re: Best way to get 13.8v to the dish ?

Nick Gregory G0HIK
 

Hi Adrian,

I had thought that on SSB/CW the battery will not have time to discharge to very much below 13.8v, Data modes will be another matter, I'll also have to uprate the PA cooling (Waterproof fan ?).

I've got some 6mm T&E around somewhere I think. A quick online calc gives me a 0.4v voltdrop, if I also use the Coax screen I can maybe knock another 0.1 to 0.15v off that figure, very acceptable.

Nick G0HIK


Re: Best way to get 13.8v to the dish ?

Adrian G4UVZ
 

Initially you talk about 13.8volts at the dish ...if you use opion 1 you will find that your battery terminal voltage on a an SLAB will very quickly become close to 12 volts. For my masthead 10GHz set up which runs on nominally 12 volts I use a 13.8 volt feed into British Standard Cooker Cable!  

Adrian


Re: Best way to get 13.8v to the dish ?

Nick Gregory G0HIK
 

Thanks Neil,

Well, initially I'm going to use the 12v amplifier I have already.

Yes, if possible as much 12v kit as possible, I will need a small inverter for the Az/El but a small 100 watt unit should suffice.

I've found the the IC-9700 is very tolerant to supply voltage and runs from batteries nicely. Looking at the circuit I see it has three DC/DC converters in there, but not on the PA supply, so I would imagine the quality of signal would start to deteriorate at 10.5v :), even though it's still giving full power out.

I had considered using a Bias Tee as I was going to used LDF4-50, now it's going to be Superflex, both have thick inners. I had not thought about using the screen on it's own though and I had not considered a P.D. imposed on the braid. Thanks for that info.

Nick G0HIK


Re: Radiall Relay ID / Info please

Bob_G1ZJP
 

Thanks Ken, Alan

 

That’s also confirmed the connectors, thanks.

 

I think a GW is probably a bit much! 😊 but nice to know you have the connectors thanks Alan.  I’ll have to see what I can use the relay for, though the connectors can hardly be classed as expensive!

 

Thanks again, both

 

73 & stay safe

 

Bob, G1ZJP

 

 

 

From: Alan Melia via groups.io
Sent: 07 May 2020 14:06
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Radiall Relay ID / Info please

 

Thanks Rainer, Eric catalogue also confirms that .....SUBVIS(SMC)...

 

Unashamed plug .....I have a quantity of goldplated SMC Male plug crimp connectors at £0.50 ea  but I am not sure what coax they are intended for, though the braid crimp outer diameter measures 3.16mm so it is quite tiny coax :-((  not really suitable for GW at 23cm :-))

 

Alan

G3NYK

----- Original Message -----

From: DF6NA Rainer

Sent: Thursday, May 07, 2020 1:19 PM

Subject: Re: [UKMicrowaves] Radiall Relay ID / Info please

 

Hi,

here you have a picture of SMB and SMC connectors. Alan is right - it is SMC.

73, Rainer


Am 07.05.2020 um 14:02 schrieb Alan Melia via groups.io:



Hi Bob I dont think anyone on the group responded to you query about the connectors on your relay. I think they are SMC but difficult to judge. There does not seem to be a geat deal of thread showing, but there is no ''ring' showing suggesting one of the push on connectors like SMB.

 

Alan

G3NYK

 

----- Original Message -----

From: Bob_G1ZJP

Sent: Thursday, May 07, 2020 9:23 AM

Subject: [UKMicrowaves] Radiall Relay ID / Info please

 

Morning All

From the depths of my junk box stock, I've found this relay [see pics]  It looks and feels "chunky" for a possible microwave capable relay, sadly it looks like it's seen better days cosmetically and has bee "got at" having a broken screw and a few with chewed heads.

Does anyone have any information about the relay please ~ maybe a spec sheet?  Does anyone know what the connectors are, please?  The relay is approx. 60mm x 60mm x 30mm.

Has anyone taken one off these relays apart and changed the connectors?  Any ideas on how to get into one?

Sorry for so many questions # to me it's a rather unusual relay and I haven't found a similar relay online.

Thanks and stay safe

73
Bob, G1ZJP

 

 


Re: Yagi v Dish on 23cms

Neil Smith G4DBN
 

I used a saddle design for Tony's 2.4m mesh dish mount, the square bar at the right side of the first pic takes a counterweight bar made from box section steel which extends a couple of feet to increase the turning moment without adding too much weight. The saddle is TIG welded 10mm ally bar, bearings are UHMWPE bushes with stainless pins. Different amounts of weight can be used for different feeds.  I made a porthole in the dish face to take the feedline through the mesh so it could go along one of the inboard quick-detach struts to minimise the feeder length from the rear-mounted equipment enclosure(s) to the feedpoint.

Neil G4DBN


On 07/05/2020 11:07, Richard GD8EXI wrote:

Thank you for your comments re dish v Yagi-Uda on 23cms. Here is a summary of the pro and cons of a dish on 23cms as I understand it.
 
Pros
·     Single feedpoint.

·     Inherently broadband so can be use on multiple bands, with appropriate feeds.

·     Less critical dimensions so more predictable results.

·     Cleaner polar diagram.

 
Cons
·     Higher windloading per dB of gain, which is inherently unbalanced about the mast.

·     Greater visual impact per dB of gain.

·     Possibly too sharp in some situations.

 
So in this basis I am drawn to a dish, particularly as there appear to be no large commercial 23cms Yagi-Uda available with the appropriate wind survival ratings.
 
However the higher windloading will probably mean I cannot get it as high and hence completely clear of all local obstructions. The asymmetric windloading is also a concern and the possibility it could vibrate. The sky dish on the corner of the house has this problem and self-destructs after about a year.
 
The dish will presumably need a counter weight to get its C of G over the mast?
 
Does anybody know of a multi band feed, which can handle 400 watts on 23cms?
 
Another issue here is that I will probably have to hire a hoist to put the dish on the mast, Yagi-Uda are more manhandleable.
 
I to have notice the dish users can be hard to find on the band but are the outstanding signals when they beam up on you. From here I work 95% of stations in a 50 deg arc so an easier search.
 
73s
Richard
GD8EXI
 
-- 
Neil
http://g4dbn.uk


Re: Radiall Relay ID / Info please

Alan Melia
 


Thanks Rainer, Eric catalogue also confirms that .....SUBVIS(SMC)...
 
Unashamed plug .....I have a quantity of goldplated SMC Male plug crimp connectors at £0.50 ea  but I am not sure what coax they are intended for, though the braid crimp outer diameter measures 3.16mm so it is quite tiny coax :-((  not really suitable for GW at 23cm :-))
 
Alan
G3NYK

----- Original Message -----
Sent: Thursday, May 07, 2020 1:19 PM
Subject: Re: [UKMicrowaves] Radiall Relay ID / Info please

Hi,

here you have a picture of SMB and SMC connectors. Alan is right - it is SMC.

73, Rainer


Am 07.05.2020 um 14:02 schrieb Alan Melia via groups.io:

Hi Bob I dont think anyone on the group responded to you query about the connectors on your relay. I think they are SMC but difficult to judge. There does not seem to be a geat deal of thread showing, but there is no ''ring' showing suggesting one of the push on connectors like SMB.
 
Alan
G3NYK
 
----- Original Message -----
From: Bob_G1ZJP
Sent: Thursday, May 07, 2020 9:23 AM
Subject: [UKMicrowaves] Radiall Relay ID / Info please

Morning All

From the depths of my junk box stock, I've found this relay [see pics]  It looks and feels "chunky" for a possible microwave capable relay, sadly it looks like it's seen better days cosmetically and has bee "got at" having a broken screw and a few with chewed heads.

Does anyone have any information about the relay please ~ maybe a spec sheet?  Does anyone know what the connectors are, please?  The relay is approx. 60mm x 60mm x 30mm.

Has anyone taken one off these relays apart and changed the connectors?  Any ideas on how to get into one?

Sorry for so many questions # to me it's a rather unusual relay and I haven't found a similar relay online.

Thanks and stay safe

73
Bob, G1ZJP


Re: Best way to get 13.8v to the dish ?

ian hope (2E0IJH)
 

I do something similar with my 23cm setup and we also use this contesting for safety
 
Ian
2E0IJH

 
 
Sent: Thursday, May 07, 2020 at 1:34 PM
From: "SAM JEWELL via groups.io" <jewell@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Best way to get 13.8v to the dish ?
A number of microwave EME ops run 110v AC from a ‘builders’ mains (yellow) transformer to the dish installation. 
Many SMPSUs will accept 100 to 240V input and allow fairly high current output at whatever voltage you want.
The advantage of this arrangement is that the (mean) ac voltage at the dish is 55V wrt ground. Whilst not pleasant you would probably survive accidental contact at these voltages.
Plugs, sockets, pre-terminated leads etc are readily available, relatively cheap, weather ‘tolerant’ and about as safe as you choose to make your installation wrt accidental contact with anything you shouldn’t touch.....
Be careful...
 
73 de Sam, G4DDK
 



Sent from Yahoo Mail for iPad
 

On Thursday, May 7, 2020, 1:22 pm, Nick Gregory G0HIK via groups.io <nickg0hik@...> wrote:

I'm on with building a small 23cms amp and DDK pre-amp at the dish. The run is about 25mtrs and current around 12 amps.

The dish is on a trailer and I intend to use it at home and also out portable.

What means do folk use to get a 13.8v to their remote amplifiers.

I've come up with three ideas

1) SLAB at the dish on trickle charge.
2) Supply 24v with regulator or DC/DC converter at the dish.
3) PSU in the shack with sense terminals.

I've discount option 4) runs mains to the dish.

Option One is my favorite at the moment as it is simple and lends itself to easily being used while out portable.

Option Two, hash from a DC/DC converter and finding a good one in budget, a linear regulator maybe better, but I would still need to arrange it to be run from batteries while out portable.

Option Three, I dont know how quick sense circuits work, i.e. speech peaks and splatter, if a sense wire fails damage from over voltage so crow bar required.

Any comments and suggestions would be great.

Nick G0HIK
 


Re: Best way to get 13.8v to the dish ?

SAM JEWELL
 

For terrestrial use I do run 16v to masthead, using thick but flexible ‘car audio’ cable. I use LDO regulators to regulate down to 11V at upto 8A for my 10W, 10GHz PA. no sense wires, just plain over engineered for voltage drop!
It’s been in place for approaching 15 years without problems.
The power is left on all the time. Quiescent power dissipation is a few watts by the transverter and some other circuits inc. a masthead OCXO.

73 de Sam, G4DDK

On Thursday, May 7, 2020, 1:52 pm, Neil Smith G4DBN <neil@...> wrote:

I'd add options like:

4) use 50V PAs or 28V PAs to reduce current demand (assuming you have a way to generate those voltages while portable)

5) send 15/16V up to the masthead with a high-current LDO (as above).

6) send 110 V AC up to the masthead as Sam suggests

Might not be easy to do any of those if you are running off batteries without an inverter.

For the "send DC up the mast" options, if you can't provide a floating negative return to the high-current supply, you need to allow for weird things happening like the coax rising a volt or more above "ground" when you are on transmit because of voltage drop across the negative lead to the PA.  If you use serious coax up the mast, you can always use the screen as one leg of the supply to save a bit of weight, but then you still have to deal with the voltage offset from the resistive drop on TX for any remote switching or monitoring unless it is optoisolated or otherwise not DC connected.

Neil G4DBN

On 07/05/2020 13:34, SAM JEWELL via groups.io wrote:
A number of microwave EME ops run 110v AC from a ‘builders’ mains (yellow) transformer to the dish installation. 
Many SMPSUs will accept 100 to 240V input and allow fairly high current output at whatever voltage you want.
The advantage of this arrangement is that the (mean) ac voltage at the dish is 55V wrt ground. Whilst not pleasant you would probably survive accidental contact at these voltages.
Plugs, sockets, pre-terminated leads etc are readily available, relatively cheap, weather ‘tolerant’ and about as safe as you choose to make your installation wrt accidental contact with anything you shouldn’t touch.....
Be careful...

73 de Sam, G4DDK




Sent from Yahoo Mail for iPad

On Thursday, May 7, 2020, 1:22 pm, Nick Gregory G0HIK via groups.io <nickg0hik@...> wrote:

I'm on with building a small 23cms amp and DDK pre-amp at the dish. The run is about 25mtrs and current around 12 amps.

The dish is on a trailer and I intend to use it at home and also out portable.

What means do folk use to get a 13.8v to their remote amplifiers.

I've come up with three ideas

1) SLAB at the dish on trickle charge.
2) Supply 24v with regulator or DC/DC converter at the dish.
3) PSU in the shack with sense terminals.

I've discount option 4) runs mains to the dish.

Option One is my favorite at the moment as it is simple and lends itself to easily being used while out portable.

Option Two, hash from a DC/DC converter and finding a good one in budget, a linear regulator maybe better, but I would still need to arrange it to be run from batteries while out portable.

Option Three, I dont know how quick sense circuits work, i.e. speech peaks and splatter, if a sense wire fails damage from over voltage so crow bar required.

Any comments and suggestions would be great.

Nick G0HIK
-- 
Neil
http://g4dbn.uk


Re: Radiall Relay ID / Info please

Bob_G1ZJP
 

Hi all

 

Thanks very much for all information, it’s all been very helpful thank you.  The catalogue from Eric showed the expected performance of the relay, sadly if I’m reading the graphs correctly, the isolation at 4GHz is only 30dB and the power handling of only 80w again starts to limit it’s use.  I had hoped that it might be a “gem” probably because of the size compared to other microwave relays.

 

What a friendly, knowledgeable group.

 

Thanks again all

 

73

Bob, G1ZJP

 

 

 

From: DF6NA Rainer
Sent: 07 May 2020 13:46
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Radiall Relay ID / Info please

 

Hi,

here you have a picture of SMB and SMC connectors. Alan is right - it is SMC.

73, Rainer


Am 07.05.2020 um 14:02 schrieb Alan Melia via groups.io:



Hi Bob I dont think anyone on the group responded to you query about the connectors on your relay. I think they are SMC but difficult to judge. There does not seem to be a geat deal of thread showing, but there is no ''ring' showing suggesting one of the push on connectors like SMB.

 

Alan

G3NYK

 

----- Original Message -----

From: Bob_G1ZJP

Sent: Thursday, May 07, 2020 9:23 AM

Subject: [UKMicrowaves] Radiall Relay ID / Info please

 

Morning All

From the depths of my junk box stock, I've found this relay [see pics]  It looks and feels "chunky" for a possible microwave capable relay, sadly it looks like it's seen better days cosmetically and has bee "got at" having a broken screw and a few with chewed heads.

Does anyone have any information about the relay please ~ maybe a spec sheet?  Does anyone know what the connectors are, please?  The relay is approx. 60mm x 60mm x 30mm.

Has anyone taken one off these relays apart and changed the connectors?  Any ideas on how to get into one?

Sorry for so many questions # to me it's a rather unusual relay and I haven't found a similar relay online.

Thanks and stay safe

73
Bob, G1ZJP

 

 


Re: Radiall Relay ID / Info please

Stephen Tompsett
 

I think the attached datasheet may be applicable, the basic series number is the same but appears to be different connection...

On 07/05/2020 11:48, Bob_G1ZJP wrote:
and these are the pictures !! ~ sorry

-- 
Stephen Tompsett (G8LYB)
Tel: 01788 578940
Mob: 07956 855816


Re: Best way to get 13.8v to the dish ?

Neil Smith G4DBN
 

I'd add options like:

4) use 50V PAs or 28V PAs to reduce current demand (assuming you have a way to generate those voltages while portable)

5) send 15/16V up to the masthead with a high-current LDO (as above).

6) send 110 V AC up to the masthead as Sam suggests

Might not be easy to do any of those if you are running off batteries without an inverter.

For the "send DC up the mast" options, if you can't provide a floating negative return to the high-current supply, you need to allow for weird things happening like the coax rising a volt or more above "ground" when you are on transmit because of voltage drop across the negative lead to the PA.  If you use serious coax up the mast, you can always use the screen as one leg of the supply to save a bit of weight, but then you still have to deal with the voltage offset from the resistive drop on TX for any remote switching or monitoring unless it is optoisolated or otherwise not DC connected.

Neil G4DBN

On 07/05/2020 13:34, SAM JEWELL via groups.io wrote:
A number of microwave EME ops run 110v AC from a ‘builders’ mains (yellow) transformer to the dish installation. 
Many SMPSUs will accept 100 to 240V input and allow fairly high current output at whatever voltage you want.
The advantage of this arrangement is that the (mean) ac voltage at the dish is 55V wrt ground. Whilst not pleasant you would probably survive accidental contact at these voltages.
Plugs, sockets, pre-terminated leads etc are readily available, relatively cheap, weather ‘tolerant’ and about as safe as you choose to make your installation wrt accidental contact with anything you shouldn’t touch.....
Be careful...

73 de Sam, G4DDK




Sent from Yahoo Mail for iPad

On Thursday, May 7, 2020, 1:22 pm, Nick Gregory G0HIK via groups.io <nickg0hik@...> wrote:

I'm on with building a small 23cms amp and DDK pre-amp at the dish. The run is about 25mtrs and current around 12 amps.

The dish is on a trailer and I intend to use it at home and also out portable.

What means do folk use to get a 13.8v to their remote amplifiers.

I've come up with three ideas

1) SLAB at the dish on trickle charge.
2) Supply 24v with regulator or DC/DC converter at the dish.
3) PSU in the shack with sense terminals.

I've discount option 4) runs mains to the dish.

Option One is my favorite at the moment as it is simple and lends itself to easily being used while out portable.

Option Two, hash from a DC/DC converter and finding a good one in budget, a linear regulator maybe better, but I would still need to arrange it to be run from batteries while out portable.

Option Three, I dont know how quick sense circuits work, i.e. speech peaks and splatter, if a sense wire fails damage from over voltage so crow bar required.

Any comments and suggestions would be great.

Nick G0HIK
-- 
Neil
http://g4dbn.uk


Re: Best way to get 13.8v to the dish ?

Nick Gregory G0HIK
 

Ive just been asked what is my dish mounted on.

It is a small boat trailer that I have shortend.

The dish mount is the standard Channel Master mounting post that fit on nicely.

I've also added a Barenco post mount that accepts the telescopic mast for beam aerials. I've also included some eye bolts for guying the telescopic mast so it needs no external guys, I've had 10 over 10 for 2 mtrs on it so far.

I intend to change the steadies for adjustable ones to make it easier to get it level now I have the dish on it.

Nick G0HIK


Re: Best way to get 13.8v to the dish ?

Nick Gregory G0HIK
 

Thanks Sam,

Yes a "Yellow" transformer sounds reasonable and it's fairly water tight too.

Ideally I want to make it all runable from batteries so I dont need a geny while out. I may end up running it from dual supplies though.

Nick G0HIK


Re: Best way to get 13.8v to the dish ?

SAM JEWELL
 

A number of microwave EME ops run 110v AC from a ‘builders’ mains (yellow) transformer to the dish installation. 
Many SMPSUs will accept 100 to 240V input and allow fairly high current output at whatever voltage you want.
The advantage of this arrangement is that the (mean) ac voltage at the dish is 55V wrt ground. Whilst not pleasant you would probably survive accidental contact at these voltages.
Plugs, sockets, pre-terminated leads etc are readily available, relatively cheap, weather ‘tolerant’ and about as safe as you choose to make your installation wrt accidental contact with anything you shouldn’t touch.....
Be careful...

73 de Sam, G4DDK

On Thursday, May 7, 2020, 1:22 pm, Nick Gregory G0HIK via groups.io <nickg0hik@...> wrote:

I'm on with building a small 23cms amp and DDK pre-amp at the dish. The run is about 25mtrs and current around 12 amps.

The dish is on a trailer and I intend to use it at home and also out portable.

What means do folk use to get a 13.8v to their remote amplifiers.

I've come up with three ideas

1) SLAB at the dish on trickle charge.
2) Supply 24v with regulator or DC/DC converter at the dish.
3) PSU in the shack with sense terminals.

I've discount option 4) runs mains to the dish.

Option One is my favorite at the moment as it is simple and lends itself to easily being used while out portable.

Option Two, hash from a DC/DC converter and finding a good one in budget, a linear regulator maybe better, but I would still need to arrange it to be run from batteries while out portable.

Option Three, I dont know how quick sense circuits work, i.e. speech peaks and splatter, if a sense wire fails damage from over voltage so crow bar required.

Any comments and suggestions would be great.

Nick G0HIK

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