Date   

Re: VAT ... it looks like it's going to be difficult.

G8DQX list
 

Dear Robin S.,

perhaps the rest of us will not be as sadly disappointed as one assumes that you will be when it is pointed out, forcefully, that fraud is not unique to any race, country, or trading arrangement. The UK has plenty of VAT fraudsters of its own, as has the EU/EEA. Given the example of Enron, and there are plenty of others, it seems that the USA has no lack of fraudsters either.

To single out China is, on the face of it, racist.

Robin, G8DQX

On 07/01/2021 18:30, Robin Szemeti - G1YFG wrote:
No problem with that, as others have said, there is no place for racism here or anywhere else, but if you are expecting me to refrain from criticising the extensive VAT and customs fraud committed by traders from the Republic of China, I'm afraid you are going to be sadly disappointed.


Re: PCB delivery

SAM JEWELL
 

Just to clarify the difference between the 2m PGA144 and the VLNA preamplifiers.
The PGA144 preamp incorporates both a notch filter at 98MHz cf as well as a carefully designed 130MHz HPF. The combined HPF and notch together create a small but significant reduction in 144MHz input circuit loss, hence improving the noise figure at 144MHz. This unusual, and possibly unique, arrangement was suggested by G4SWX some years ago during development of the PGA144. It follows on from some older low loss HPF input work by DJ7VY, LA8AK and others.
The low Q bandpass output filter is designed to not only enhance gain at 144MHz but also to roll off gain above the band.
The variable output attenuator allows gain setting as required.
The PGA144 is not a high gain, wideband, preamplifier, like the VLNA designs, which are meant for EME where second stage contribution needs to be minimised together with the lowest loss input matching arrangement.
The dynamic range of the PGA144 is way above most earlier GaAs mesFet and HEMT preamplifiers. You need a pretty good following receiver to take advantage of the PGA144 dynamic range!

73 de Sam,  G4DDK



On 8 d 130MHz HPFJan 2021, at 18:04, David Redman <nt I@...> wrote:
 Years ago

Yes Sam's preamps are excellent for low noise and high gain, just what you need for dish mounted preamps.
D
Dedending on da to be minimisedyour local RF signal levels 50 to 1600MHz for terrestrial use and depending on your levels of Band 2 FM, 220MHz ish DAB, UHF digital TV and then cell phoness gain setting plus reminent vhf / uhf pmr plus pagers  you may need a decent BPF ahead of the pre-amp.
I use Sam's preamps on 2m, 23cms and 9cms EME and they are excellent but be aware for tropo use they are relatively wideband input. 

Dave
G4IDR 



Re: MMIC's

Colin Ranson
 

Just one last thing Geoff,   did you use a 2 pole TOKO filter at 1242MHz or did you by-pass ? Maybe no need for a filter in that position if you are multiplying ?

 

Regards

 

Colin

 

Sent from Mail for Windows 10

 

From: geoffrey pike via groups.io
Sent: 08 January 2021 17:47
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] MMIC's

 

Hi Colin,

Doing somethimg similar just to do something!, anyway DDK microwave source pcb 103.5 MHz Xtal output at 1242 MHz (this has needed a job so iam using it), this drives a MCL VNA-25 mmic at about 4dBm this then goes into a pipe cap filter at 2484 MHz, then another VNA-25 with -8dB ahead of it to give 14dBm at 2484 Mhz then into the W1MHZ quadrupler for about 8 dBm out at 9936 MHz to drive a Minicircuits mixer and mix with 432 MHz. The VNA-25 is a small outline 8 pin DIL device so a bit different to usuall mmic. About 14 dB gain and 17dBm out at 2,5 GHz. 

cheers

Geoff

GI0GDP

 

On Friday, 8 January 2021, 14:03:52 GMT, Colin Ranson <g8lbs@...> wrote:

 

 

Hi all,

 

I have repurposed a DDK 2008 L band source from 96MHz to 106.5MHz with an output of 1278MHz.  The original was extended to include a PGA103+ to bump up the output to feed a high level mixer.   

 

 

Thinks ?  could I use this MMIC as a doubler to 2256MHz ? I understand from texts that it has to be operated in a non-linear fashion)  At the moment its biased to 3.5v and I have removed a level determining attenuator so I am hitting the MMIC quite hard. I am detecting very little at 2556MHz at the moment. (not enough to drive my Qualcom x 4 multiplier to 10.224GHz)

 

Can anyone give me a ballpark figure to set the bias to please ? And is this likely to work well enough ? I have not tried this method before so hopefully with enough 2256MHz I will include a ‘stop-end’ filter and enough gain to give me 3dbm at the Qualcom Mult input. Getting the 10dbm output (after filtering) for the mixer(s) will be another matter.

 

Best regards to all, keep those soldering irons hot !

 

Regards, Colin de G8LBS.

 

 

 

Sent from Mail for Windows 10

 

 


Re: MMIC's

Colin Ranson
 

Hi Geoff,

 

Ha !   waiting for a couple of 35mm (or so) pipe caps to make a 2556MHz filter. I hope to align these using a noise source and my SAA-N2 VNA.  Wonder what size caps you used ? I have some 28mm here so it might be a toss-up between the two sizes.

 

Glad to see people on the RF make !

 

73’s   Colin.

 

Sent from Mail for Windows 10

 

From: geoffrey pike via groups.io
Sent: 08 January 2021 17:47
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] MMIC's

 

Hi Colin,

Doing somethimg similar just to do something!, anyway DDK microwave source pcb 103.5 MHz Xtal output at 1242 MHz (this has needed a job so iam using it), this drives a MCL VNA-25 mmic at about 4dBm this then goes into a pipe cap filter at 2484 MHz, then another VNA-25 with -8dB ahead of it to give 14dBm at 2484 Mhz then into the W1MHZ quadrupler for about 8 dBm out at 9936 MHz to drive a Minicircuits mixer and mix with 432 MHz. The VNA-25 is a small outline 8 pin DIL device so a bit different to usuall mmic. About 14 dB gain and 17dBm out at 2,5 GHz. 

cheers

Geoff

GI0GDP

 

On Friday, 8 January 2021, 14:03:52 GMT, Colin Ranson <g8lbs@...> wrote:

 

 

Hi all,

 

I have repurposed a DDK 2008 L band source from 96MHz to 106.5MHz with an output of 1278MHz.  The original was extended to include a PGA103+ to bump up the output to feed a high level mixer.   

 

 

Thinks ?  could I use this MMIC as a doubler to 2256MHz ? I understand from texts that it has to be operated in a non-linear fashion)  At the moment its biased to 3.5v and I have removed a level determining attenuator so I am hitting the MMIC quite hard. I am detecting very little at 2556MHz at the moment. (not enough to drive my Qualcom x 4 multiplier to 10.224GHz)

 

Can anyone give me a ballpark figure to set the bias to please ? And is this likely to work well enough ? I have not tried this method before so hopefully with enough 2256MHz I will include a ‘stop-end’ filter and enough gain to give me 3dbm at the Qualcom Mult input. Getting the 10dbm output (after filtering) for the mixer(s) will be another matter.

 

Best regards to all, keep those soldering irons hot !

 

Regards, Colin de G8LBS.

 

 

 

Sent from Mail for Windows 10

 

 


Re: PCB delivery

David Redman
 

Yes Sam's preamps are excellent for low noise and high gain, just what you need for dish mounted preamps.

Dedending on your local RF signal levels 50 to 1600MHz for terrestrial use and depending on your levels of Band 2 FM, 220MHz ish DAB, UHF digital TV and then cell phones plus reminent vhf / uhf pmr plus pagers  you may need a decent BPF ahead of the pre-amp.
I use Sam's preamps on 2m, 23cms and 9cms EME and they are excellent but be aware for tropo use they are relatively wideband input. 

Dave
G4IDR 




On Fri, 8 Jan 2021, 17:41 Robin Szemeti - G1YFG, <robin@...> wrote:
Hi Martin,

Sam Jewell's preamps are excellent on 23cm, but you do need to put an attenuator in the output for terrestrial use if you are intending to do contest from a reasonable location, or it does tend to get a bit loud!  These pre's were just a bit of fun really, the 70cm one has a self-adjusting bias ... the 2m one is a little more conventional, with a pot for the bias.
image.png

image.png


Off topic ...

I'm also planning to use OpenCPN on the boat, when and if I can get back to it, as it is in Wales.  I have shiny new B&G hull sensors and wind instrument,  hoping to drop the NMEA2000 outputs into SignalK and pick them up as needed for the plotters. I'll still keep Navionics on a tablet though, as that works really well.  I'm looking forward to integrating the AIS into that.

I understand the problems of the Helford river, we are in the Menai Strait so have all the fun of navigating the currents and shallows with either The Swellies or Caernarfon Bar to cross to get out.  The boat did not make it into the water last year due to the lockdown in Wales we coudl not get access to finish the tasks and it is locked down again. hopefully this year will be better, as last year was just a complete money pit for a toy I could not use ... my other toy has wings,  that was even worse.


--
Robin Szemeti - G1YFG


Re: MKU 13 G3 Schematic

geoffrey pike
 

Hi Conrad,
The Franco PCBs SU-02 have 4 on each, but you will need to de solder them
Geoff
GI0GDP

On Friday, 8 January 2021, 09:24:06 GMT, Conrad, PA5Y <g0ruz@...> wrote:


Yes the G2 schematic is available from the Kuhne archives, I suppose what I should have said was. I have the G2 schematic, is the front end the same for the G3? I have a G3. I suspect that the front end is indeed the sane. Which leads me to the next question. Where can I get a few NE32584Cs?

73

Conrad PA5Y



From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of DF6NA Rainer via groups.io <df6na@...>
Sent: 08 January 2021 07:04
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] MKU 13 G3 Schematic
 

It's correct !!!

Am 07.01.2021 um 23:40 schrieb Graham G3VKV via groups.io:
    DB6NT 13cms G2 front end FET is an NE32584C

                                                    Graham G3VKV


Re: MMIC's

geoffrey pike
 

Hi Colin,
Doing somethimg similar just to do something!, anyway DDK microwave source pcb 103.5 MHz Xtal output at 1242 MHz (this has needed a job so iam using it), this drives a MCL VNA-25 mmic at about 4dBm this then goes into a pipe cap filter at 2484 MHz, then another VNA-25 with -8dB ahead of it to give 14dBm at 2484 Mhz then into the W1MHZ quadrupler for about 8 dBm out at 9936 MHz to drive a Minicircuits mixer and mix with 432 MHz. The VNA-25 is a small outline 8 pin DIL device so a bit different to usuall mmic. About 14 dB gain and 17dBm out at 2,5 GHz. 
cheers
Geoff
GI0GDP

On Friday, 8 January 2021, 14:03:52 GMT, Colin Ranson <g8lbs@...> wrote:


Hi all,

 

I have repurposed a DDK 2008 L band source from 96MHz to 106.5MHz with an output of 1278MHz.  The original was extended to include a PGA103+ to bump up the output to feed a high level mixer.   

 

 

Thinks ?  could I use this MMIC as a doubler to 2256MHz ? I understand from texts that it has to be operated in a non-linear fashion)  At the moment its biased to 3.5v and I have removed a level determining attenuator so I am hitting the MMIC quite hard. I am detecting very little at 2556MHz at the moment. (not enough to drive my Qualcom x 4 multiplier to 10.224GHz)

 

Can anyone give me a ballpark figure to set the bias to please ? And is this likely to work well enough ? I have not tried this method before so hopefully with enough 2256MHz I will include a ‘stop-end’ filter and enough gain to give me 3dbm at the Qualcom Mult input. Getting the 10dbm output (after filtering) for the mixer(s) will be another matter.

 

Best regards to all, keep those soldering irons hot !

 

Regards, Colin de G8LBS.

 

 

 

Sent from Mail for Windows 10

 


Re: PCB delivery

Robin Szemeti - G1YFG
 

Hi Martin,

Sam Jewell's preamps are excellent on 23cm, but you do need to put an attenuator in the output for terrestrial use if you are intending to do contest from a reasonable location, or it does tend to get a bit loud!  These pre's were just a bit of fun really, the 70cm one has a self-adjusting bias ... the 2m one is a little more conventional, with a pot for the bias.
image.png

image.png


Off topic ...

I'm also planning to use OpenCPN on the boat, when and if I can get back to it, as it is in Wales.  I have shiny new B&G hull sensors and wind instrument,  hoping to drop the NMEA2000 outputs into SignalK and pick them up as needed for the plotters. I'll still keep Navionics on a tablet though, as that works really well.  I'm looking forward to integrating the AIS into that.

I understand the problems of the Helford river, we are in the Menai Strait so have all the fun of navigating the currents and shallows with either The Swellies or Caernarfon Bar to cross to get out.  The boat did not make it into the water last year due to the lockdown in Wales we coudl not get access to finish the tasks and it is locked down again. hopefully this year will be better, as last year was just a complete money pit for a toy I could not use ... my other toy has wings,  that was even worse.


--
Robin Szemeti - G1YFG


Re: PCB delivery

Paul Randall G3NJV
 

Haha, probably not.  
Got a new aerial group to go up for 2,70 & 23, only modest,  for 24/7 all weather use so the pre-amps sound ideal, just need to source one for 23cm. Was looking around wondering what to get. 

You sound super productive,  all those projects.  Hopefully you'll get the boat in this year.  Our yard has locked us out again,  hopefully lifted by april?

I found a very economical German Class B  AIS on ebay - bit of a last minute change as I had only planned to fit a Rx. The now unwanted rx is being used as a propagation monitor feeding the sentences into a nmeatools nmea to Wi-Fi box. Opencpn base map is good enough to show me what vhf is doing on my phone. 

Same setep on the boat I can have as many "no wires" chartplotters aboard as I want, works really well and a super feature is that i can grab kap ? Charts taken from Google earth satellite images that overlay vector cmap charts - super accurate you can calibrate the commercial charts and super useful - real  images of anchorages, mooring buoys in harbours, marinas etc and by a great stroke of luck,  the images of the Helford river were taken at low tide so show the narrow tortuous deep channel thru the mud we have to negociate to get to/ from the boatyard every year. Clearance less that 0.3m in places so have to position the boat within a metre or so. Helps a lot but we invariably go aground anyway haha.   

Happy New year Robin
Paul



Sent from my Galaxy



-------- Original message --------
From: Robin Szemeti - G1YFG <robin@...>
Date: 08/01/2021 13:28 (GMT+00:00)
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] PCB delivery

Certainly!  I'll build up a couple to check them .. they are more a "contest" HA8ET style LNA than a high gain EME style one. They feature a suitable "notch" on the input for 432 or 144, an output filter for 432 or 144 and a protection relay on the input to try and preserve the LNA when sitting on the end of a relay that may have QRO on the transmit port, a pot is provided on the output so you can set it for just enough gain ... they should fit the standard tinplate boxes.

Let me build them up and get back to you, I have cocked them up, you never know ;)

On Fri, 8 Jan 2021 at 12:48, Paul Randall G3NJV <paulfrandall@...> wrote:
Hi Robin, any lna boards going spare?
Hope you are well
Paul



Sent from my Galaxy



-------- Original message --------
From: Robin Szemeti - G1YFG <robin@...>
Date: 08/01/2021 12:25 (GMT+00:00)
Subject: [UKMicrowaves] PCB delivery

Nice delivery of pcbs today, the 9cm transverter is the one that I'm looking forward to building up.

There is another batch of CANFI noise heads, but my pick and place is in bits at the moment,  i 'll try and sort that, and mount the components, otherwise they'll have to go out as kits.

There are some 2m and 70cm LNA, some mmic boards for a friend and an AIS transceiver for my boat. Plenty of RF  projects to keep me busy.

--
Robin Szemeti - G1YFG


--
Robin Szemeti - G1YFG


Re: MMIC's

Colin Ranson
 

Thanks Andy,

 

I had forgotten the lowish gain at 2.5GHz,

 

I have some GALI-2, same case style, nice and robust , good to 8GHz, so will try one of those.

 

Will let you know how it works, or doesn’t !

 

Regards

 

Colin. G8LBS

 

Sent from Mail for Windows 10

 

From: Andy G4JNT
Sent: 08 January 2021 15:56
To: UK Microwaves groups.io
Subject: Re: [UKMicrowaves] MMIC's

 

Need tp add, that was with ERA devices.    The PGA is a somewhat lower frequency thingumybob  and perhaps not the best choice for a multiplier to S-Band

 

Andy

 

 

 

On Fri, 8 Jan 2021 at 14:47, Andy Talbot <andy.g4jnt@...> wrote:

An MSA MMIC, a MSA-2 IIRC, was used as a frequency doubler in the Frequency Generation Unit on the Inmarsat-3 satellite back in the 1990s.   

And if it's OK in space, is more than OK terrestrially!   

 

Just bias it as normal, or perhaps to 50 - 75% of normal current, and drive to saturation.

 

I've done it as both tripler and quadrupler from 2.5 or 3.4GHz to 10GHz

 

 

Andy

 

 

On Fri, 8 Jan 2021 at 14:04, Colin Ranson <g8lbs@...> wrote:

Hi all,

 

I have repurposed a DDK 2008 L band source from 96MHz to 106.5MHz with an output of 1278MHz.  The original was extended to include a PGA103+ to bump up the output to feed a high level mixer.   

 

 

Thinks ?  could I use this MMIC as a doubler to 2256MHz ? I understand from texts that it has to be operated in a non-linear fashion)  At the moment its biased to 3.5v and I have removed a level determining attenuator so I am hitting the MMIC quite hard. I am detecting very little at 2556MHz at the moment. (not enough to drive my Qualcom x 4 multiplier to 10.224GHz)

 

Can anyone give me a ballpark figure to set the bias to please ? And is this likely to work well enough ? I have not tried this method before so hopefully with enough 2256MHz I will include a ‘stop-end’ filter and enough gain to give me 3dbm at the Qualcom Mult input. Getting the 10dbm output (after filtering) for the mixer(s) will be another matter.

 

Best regards to all, keep those soldering irons hot !

 

Regards, Colin de G8LBS.

 

 

 

Sent from Mail for Windows 10

 

 


Re: MMIC's

Andy G4JNT
 

Need tp add, that was with ERA devices.    The PGA is a somewhat lower frequency thingumybob  and perhaps not the best choice for a multiplier to S-Band



On Fri, 8 Jan 2021 at 14:47, Andy Talbot <andy.g4jnt@...> wrote:
An MSA MMIC, a MSA-2 IIRC, was used as a frequency doubler in the Frequency Generation Unit on the Inmarsat-3 satellite back in the 1990s.   
And if it's OK in space, is more than OK terrestrially!   

Just bias it as normal, or perhaps to 50 - 75% of normal current, and drive to saturation.

I've done it as both tripler and quadrupler from 2.5 or 3.4GHz to 10GHz


Andy


On Fri, 8 Jan 2021 at 14:04, Colin Ranson <g8lbs@...> wrote:

Hi all,

 

I have repurposed a DDK 2008 L band source from 96MHz to 106.5MHz with an output of 1278MHz.  The original was extended to include a PGA103+ to bump up the output to feed a high level mixer.   

 

 

Thinks ?  could I use this MMIC as a doubler to 2256MHz ? I understand from texts that it has to be operated in a non-linear fashion)  At the moment its biased to 3.5v and I have removed a level determining attenuator so I am hitting the MMIC quite hard. I am detecting very little at 2556MHz at the moment. (not enough to drive my Qualcom x 4 multiplier to 10.224GHz)

 

Can anyone give me a ballpark figure to set the bias to please ? And is this likely to work well enough ? I have not tried this method before so hopefully with enough 2256MHz I will include a ‘stop-end’ filter and enough gain to give me 3dbm at the Qualcom Mult input. Getting the 10dbm output (after filtering) for the mixer(s) will be another matter.

 

Best regards to all, keep those soldering irons hot !

 

Regards, Colin de G8LBS.

 

 

 

Sent from Mail for Windows 10

 


Re: MMIC's

Andy G4JNT
 

An MSA MMIC, a MSA-2 IIRC, was used as a frequency doubler in the Frequency Generation Unit on the Inmarsat-3 satellite back in the 1990s.   
And if it's OK in space, is more than OK terrestrially!   

Just bias it as normal, or perhaps to 50 - 75% of normal current, and drive to saturation.

I've done it as both tripler and quadrupler from 2.5 or 3.4GHz to 10GHz


Andy


On Fri, 8 Jan 2021 at 14:04, Colin Ranson <g8lbs@...> wrote:

Hi all,

 

I have repurposed a DDK 2008 L band source from 96MHz to 106.5MHz with an output of 1278MHz.  The original was extended to include a PGA103+ to bump up the output to feed a high level mixer.   

 

 

Thinks ?  could I use this MMIC as a doubler to 2256MHz ? I understand from texts that it has to be operated in a non-linear fashion)  At the moment its biased to 3.5v and I have removed a level determining attenuator so I am hitting the MMIC quite hard. I am detecting very little at 2556MHz at the moment. (not enough to drive my Qualcom x 4 multiplier to 10.224GHz)

 

Can anyone give me a ballpark figure to set the bias to please ? And is this likely to work well enough ? I have not tried this method before so hopefully with enough 2256MHz I will include a ‘stop-end’ filter and enough gain to give me 3dbm at the Qualcom Mult input. Getting the 10dbm output (after filtering) for the mixer(s) will be another matter.

 

Best regards to all, keep those soldering irons hot !

 

Regards, Colin de G8LBS.

 

 

 

Sent from Mail for Windows 10

 


Re: PCB delivery

Robin Szemeti - G1YFG
 

Yes it is, google "peterantypas AIS" .. I have 5 boards here and only really need one, and an SMT paste stencil ... I may even have spares of the two "hard to get" chips, the SiRadio devices and the skytronics RF switch .. ping me offlist, it is radio related, but I doubt the uWave lot want to hear us prattling on about boaty digital comms.

On Fri, 8 Jan 2021 at 14:17, Martin Phillips G4CIO <martin@...> wrote:
<OT> Hi Robin, is the AIS tcvr a published design? I've been thinking for a while that we could do with one on one of our boats...</OT>

Martin/

On 8/1/21 12:25 PM, Robin Szemeti - G1YFG wrote:
Nice delivery of pcbs today, the 9cm transverter is the one that I'm looking forward to building up.

There is another batch of CANFI noise heads, but my pick and place is in bits at the moment,  i 'll try and sort that, and mount the components, otherwise they'll have to go out as kits.

There are some 2m and 70cm LNA, some mmic boards for a friend and an AIS transceiver for my boat. Plenty of RF  projects to keep me busy.

--
Robin Szemeti - G1YFG



--
Robin Szemeti - G1YFG


Re: PCB delivery

Martin Phillips G4CIO
 

<OT> Hi Robin, is the AIS tcvr a published design? I've been thinking for a while that we could do with one on one of our boats...</OT>

Martin/

On 8/1/21 12:25 PM, Robin Szemeti - G1YFG wrote:
Nice delivery of pcbs today, the 9cm transverter is the one that I'm looking forward to building up.

There is another batch of CANFI noise heads, but my pick and place is in bits at the moment,  i 'll try and sort that, and mount the components, otherwise they'll have to go out as kits.

There are some 2m and 70cm LNA, some mmic boards for a friend and an AIS transceiver for my boat. Plenty of RF  projects to keep me busy.

--
Robin Szemeti - G1YFG



Re: Re elevation on a dish

John Fell
 

Hi Dave ,
I had a 20W TWT based system up this mast for over 20 years before moving on to use bits of it for 10GHz EME at G4RFR .

The first G to G contact on 10GHz (CW) used the TVTR - 1994 between G4RFR and G3WDG , using 12 Ft prime focus 0.43f/D dish at our end.

The TVTR was quite a load for my 30Ft Western Ulimast and restricted other band antenna deployment a bit .....feeding all TWT rails up rotator style multicore cables ......
My TVTR used original G3WDG modules with a modified 4 port WG16 on its front end , with the 2 stages of LNA directly on the RX port and TWT output on the TX port .The feed was a G3PHO type WG 16 flanged and feeding the 4 port switch via EW90 elliptical waveguide .Probably had about 1 m total between the feed and the front end LNA .
For tropo use this still represents a reasonable insertion loss . You can easily make ur own EW90 flanges to marry standard WG16 flanged ports .
Form the required bends into the EW90 - using gentle bends by hand /vice.

A 10W system at the dish will form a potent terrestrial system , but do spend the time to Engineer the housing to prevent condensation .An inverted bucket format is good as it allows airflow and if you take all services in via the open end rain tends to stay out .( worked a few with 10W TWT last year on the 12Ft dish - on 10GHz CW ) . The 200W TWT makes for louder echoes though .

From home I am only operational on RX on 10GHz , but having £10 LNBs and GPS reference locking makes it a potent and cheap thing to do .

73
John
G0API

On Fri, 8 Jan 2021 at 11:33, Dave via groups.io <davidnewman55=icloud.com@groups.io> wrote:
Hello John,
Thanks very much indeed for photos of your system. Yes, I take your point about spacing the dish far away enough to get 30 degrees of elevation. I am torn between using a  waveguide feed or preamp at the feedpoint.
I will look at the limits of the Jack very carefully in the workshop as you suggested. 
If your system has lasted for so long it must be very rugged and well constructed. 
Thanks again for all the pointers.
73
Dave G4GLT. 

On 8 Jan 2021, at 10:55, John Fell <john.g0api@...> wrote:


Hi Dave ,
Had to wait for the frost to lift to take these pics .
My masthead 60cm dish and Elevation system .

18" jack used with base end pivot made from 3" exhaust clamp around the standard Scaf pole mast extension above KR600 inside cage support ( just below bottom of pic).Extra large clamp allows one leg of U bolt to be fitted with a turned alum sleeve spacer to take the eye of the base balljoint of the jack.Also allows positional adjustment to set up desired stroke/maximum dish travel..

Top end of jack fits onto a welded pivot bolt attached to underside of a 2 x 1" steel hollow section , welded or bolted to a steel stand-off plate that has a steel hinge at the mast end .The other end of the hinge is welded to a steel Scaf clamp , which again can be adjusted to setup the final geometry .

The dish is mounted on 1.25" dimeter steel tube that came with it - in this case it is a 90 degree bent item so that is why the 2X1" hollow section is used to offset the dish tube and put the vertical load thrust on the centre line of the vertical mast .Room to add masthead PA/front end housings just behind the dish , without adding much loading to the feed arm etc .

You will notice the system puts the offset dish well forward offset to the mast - this allows the top rim of the dish to travel to an effective 30 degrees of Elevation .
That allows pointing at QO100 and well above ground noise sources for Sun noise  measurements and I have decoded DL0SHF several times over last few years .Other antennas on mast above are positioned to offset the dish system , again putting the vertical loading equally about the rotator cage .

The small box on a standoff 1"x1/8" aluminium flat bar just in front and below dish base  is housing a G4JNT AZ/EL digital sensor .

Which ever system you build make sure the jack is adjusted so its internal limit switches limit the travel within limits that protect the dish - I managed to fold this dish at the top with 12V supply and the only thing I noticed was a sudden rise in ground noise !

After 30+ years up the mast the only thing that needed replacement was the jack ( running leadscrew nut fractured ) -  the light coloured cylinder on the jack is an old aluminium Dow Corning Vacuum oil can - this covers the top end jack seal to prevent rain getting in when/if the seal cracks - smother all surfaces in Waxoil ....

73
John
G0API

On Thu, 7 Jan 2021 at 17:03, Dave via groups.io <davidnewman55=icloud.com@groups.io> wrote:
Hello,
I am adding elevation on a dish for tropo only (not EME) and wondered if anyone has a photo of the mechanics of it, preferably with some sort of hinge . I have an actuator which has a stroke length of 4 inches. I think the lower part of the dish will have to be pushed outwards.
73
Dave G4GLT.





<DSCF7244.JPG>
<DSCF7245.JPG>


MMIC's

Colin Ranson
 

Hi all,

 

I have repurposed a DDK 2008 L band source from 96MHz to 106.5MHz with an output of 1278MHz.  The original was extended to include a PGA103+ to bump up the output to feed a high level mixer.   

 

 

Thinks ?  could I use this MMIC as a doubler to 2256MHz ? I understand from texts that it has to be operated in a non-linear fashion)  At the moment its biased to 3.5v and I have removed a level determining attenuator so I am hitting the MMIC quite hard. I am detecting very little at 2556MHz at the moment. (not enough to drive my Qualcom x 4 multiplier to 10.224GHz)

 

Can anyone give me a ballpark figure to set the bias to please ? And is this likely to work well enough ? I have not tried this method before so hopefully with enough 2256MHz I will include a ‘stop-end’ filter and enough gain to give me 3dbm at the Qualcom Mult input. Getting the 10dbm output (after filtering) for the mixer(s) will be another matter.

 

Best regards to all, keep those soldering irons hot !

 

Regards, Colin de G8LBS.

 

 

 

Sent from Mail for Windows 10

 


Re: PCB delivery

Robin Szemeti - G1YFG
 

Certainly!  I'll build up a couple to check them .. they are more a "contest" HA8ET style LNA than a high gain EME style one. They feature a suitable "notch" on the input for 432 or 144, an output filter for 432 or 144 and a protection relay on the input to try and preserve the LNA when sitting on the end of a relay that may have QRO on the transmit port, a pot is provided on the output so you can set it for just enough gain ... they should fit the standard tinplate boxes.

Let me build them up and get back to you, I have cocked them up, you never know ;)


On Fri, 8 Jan 2021 at 12:48, Paul Randall G3NJV <paulfrandall@...> wrote:
Hi Robin, any lna boards going spare?
Hope you are well
Paul



Sent from my Galaxy



-------- Original message --------
From: Robin Szemeti - G1YFG <robin@...>
Date: 08/01/2021 12:25 (GMT+00:00)
Subject: [UKMicrowaves] PCB delivery

Nice delivery of pcbs today, the 9cm transverter is the one that I'm looking forward to building up.

There is another batch of CANFI noise heads, but my pick and place is in bits at the moment,  i 'll try and sort that, and mount the components, otherwise they'll have to go out as kits.

There are some 2m and 70cm LNA, some mmic boards for a friend and an AIS transceiver for my boat. Plenty of RF  projects to keep me busy.

--
Robin Szemeti - G1YFG


--
Robin Szemeti - G1YFG


WTB: Continental microwave 432MHz 150W PA or similar

Conrad, PA5Y
 

I already have a 50W Continental 432MHz PA, it is very linear. For my new system I need a little bit more power. I understand that there is a 150W version of the Continental amplifiers? Does anyone have one or something similar that they are willing to sell? Main requirement is that it is very linear at around 75W PEP. 

Only tentative enquiry at this stage. I need to get the antennas up first.

73

Conrad PA5Y


Re: PCB delivery

Paul Randall G3NJV
 

Hi Robin, any lna boards going spare?
Hope you are well
Paul



Sent from my Galaxy



-------- Original message --------
From: Robin Szemeti - G1YFG <robin@...>
Date: 08/01/2021 12:25 (GMT+00:00)
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] PCB delivery

Nice delivery of pcbs today, the 9cm transverter is the one that I'm looking forward to building up.

There is another batch of CANFI noise heads, but my pick and place is in bits at the moment,  i 'll try and sort that, and mount the components, otherwise they'll have to go out as kits.

There are some 2m and 70cm LNA, some mmic boards for a friend and an AIS transceiver for my boat. Plenty of RF  projects to keep me busy.

--
Robin Szemeti - G1YFG


PCB delivery

Robin Szemeti - G1YFG
 

Nice delivery of pcbs today, the 9cm transverter is the one that I'm looking forward to building up.

There is another batch of CANFI noise heads, but my pick and place is in bits at the moment,  i 'll try and sort that, and mount the components, otherwise they'll have to go out as kits.

There are some 2m and 70cm LNA, some mmic boards for a friend and an AIS transceiver for my boat. Plenty of RF  projects to keep me busy.

--
Robin Szemeti - G1YFG

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