Date   

Re: 24 GHz

John Quarmby
 

Hi Gerard

My 24GHz system is not permanently on the tower during the winter but only takes 30 minutes to install. It will be up there when there is tropo or a good chance of rainscatter.

3W to 48cm PF dish JO02OB.

73

John G3XDY

On 30/01/2021 15:24, gerard.geesink@... wrote:
Gentleman,

24G season will be starting soon. Who of you is permanently QRV? 
Here 2.5W 1.1 m dish ... JO31FX.

73 Gerard PA0BAT

Op 30 jan. 2021 3:19 p.m. schreef "Steve G4HTZ via groups.io" <essexsteve@...>:
Hi Denis 
this may be an option from I0JXX 

https://www.i0jxx.com/gb/116-24-ghz

--
Steve G4HTZ 
JO01JN60
Great Wakering, Essex 
24ghz 1.8w 80cm dish 

also known to be active occasionally on 70cms DATV 


Virus-free. www.avast.com


Re: 24 GHz Feed Horn

Dominique Dehays
 

Hi all,

Personnaly I would avoid a horn using tuning screws like the 3cm JXX , I can understand mr Joe Ham uses tuning screws on his home made horn , but not on a commercial horn

73
Dom


Re: 24 GHz Feed Horn

Denis Stanton G0OLX
 

I0JXX have just sent me a Login code so that I can now place a order
Lets see how I get on
Thanks everybody Best 73's


24 GHz

Gerard Geesink
 

Gentleman,

24G season will be starting soon. Who of you is permanently QRV? 
Here 2.5W 1.1 m dish ... JO31FX.

73 Gerard PA0BAT

Op 30 jan. 2021 3:19 p.m. schreef "Steve G4HTZ via groups.io" <essexsteve@...>:

Hi Denis 
this may be an option from I0JXX 

https://www.i0jxx.com/gb/116-24-ghz

--
Steve G4HTZ 
JO01JN60
Great Wakering, Essex 
24ghz 1.8w 80cm dish 

also known to be active occasionally on 70cms DATV 


Re: 24 GHz Feed Horn

Denis Stanton G0OLX
 

Neil
Thanks for the offer on the 24 GHz horn
I0JXX looks good if I can get one!!!! I might also go for the 10GHz feed horn as well
It may be the customs problem after brexit as there is not a UK or GI listing in the countries lists
I will let you all know how I get on
Best 73’s


On 30 Jan 2021, at 15:12, Denis Stanton G0OLX via groups.io <Stantondenis@...> wrote:

Steve
Just went to order one but would not take UK address details.
The 10Ghz feed looks good as well
I wonder why the UK dos'nt appear in the countries list.
Will wait to I get to work on Tuesday and give them a ring
Many thanks for info
Denis
G0OLX


Re: 24 GHz Feed Horn

Denis Stanton G0OLX
 

Steve
Just went to order one but would not take UK address details.
The 10Ghz feed looks good as well
I wonder why the UK dos'nt appear in the countries list.
Will wait to I get to work on Tuesday and give them a ring
Many thanks for info
Denis
G0OLX


Re: 24 GHz Feed Horn

Denis Stanton G0OLX
 

Thanks Steve that looks very interesting
Denis G0OLX


Re: 24 GHz Feed Horn

Steve G4HTZ
 

Hi Denis 
this may be an option from I0JXX 

https://www.i0jxx.com/gb/116-24-ghz

--
Steve G4HTZ 
JO01JN60
Great Wakering, Essex 
24ghz 1.8w 80cm dish 

also known to be active occasionally on 70cms DATV 


24 GHz Feed Horn

Denis Stanton G0OLX
 

Hi All
Any body out tyhere got a RF ham Design 24HG2 Milled Horn surplas they want to sell on
Many thanks
Denis
G0OLX


Re: Anyone got any spare WG15 / WR112 waveguide

g4cch_1
 
Edited

I'm in touch with Mark GM4ISM about WG14, so no need to look further.

Howard, G4CCH


Re: round attenuator dissasembly?

Robin Szemeti - G1YFG
 

While I would agree with you that Be Oxide is nasty stuff, beryl copper is relatively benign and has been used for non-sparking hand tools for many decades without issue. It can safely be cut and drilled without risk, although you may not want to sand it.

On Sat, 30 Jan 2021 at 12:14, alwyn.seeds1 <a.seeds@...> wrote:
Dear All,

The very common hazards in electronics are BeO thermal links and Beryllium Copper alloys used in spring stock and in RF vacuum device construction.

Eimac Varian used to include BeO hazard sheets with most of their valves and I remember long debates as to whether the insulating seals in 4CX250Bs were Beryllium Oxide- I think it was decided that they were not, though the thermal links of conduction cooled versions were. External anodes frequently used Beryllium Copper for better machining- machinists often suffered from lung disease, though it may have been incorrectly attributed to smoking.

Lots of RF power transistors from the 1960s to the 1980s used BeO packaging for better heat conductivity and RF attenuators/loads frequently deposit the resistive element on BeO, again for better heat conductivity.

So I would not dismantle a BeO containing device and would be careful cutting up old valves which may contain a variety of toxic substances as well as the Beryllium Copper hazard.

Those who worked in the manufacturers would know more.

Regards,

Alwyn G8DOH

   
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


--
Robin Szemeti - G1YFG


Re: Anyone got any spare WG15 / WR112 waveguide

John Fell
 

Nice plots Howard .
I dug out some EVOs that I made for various EME related projects .Couple of pics below showing 2400MHz in WG16 , 3400MHz in WG 16 and the 5700MHz one that Andy made up for me in WR28 .

The insertion loss of the 2400MHz was 8dB , which between a DDK first stage and  an external secondary stage at EME feed area , would be fine .

Much lower insertion loss on 3400MHz and 5.7GHz , so Ok for LO and RF duty.

73
John
G0API

It am raining here too

On Sat, 30 Jan 2021 at 12:19, g4cch_1 <g4cch_1@...> wrote:

[Edited Message Follows]

Thanks Andy, and I will take your advice...

I build stuff, and experiment, even though I don't always know what I am doing.
Eventually I get there, well most of the time...

So I am looking for WG14 (WR137), but will take WG15 (WR112) if anyone has any to spare.
I have some WG16, but not enough to waste, so may need some more of anyone has some to spare.

I built a filter using WG17 just because I had some, and used dimensions for this QEX article:
http://www.w1ghz.org/filter/QEX_Mar_2010_p23-29.pdf

I realised later that the WG17 was for a 5.7GHz filter.

Anyway, the filter did eventually tune down to 2.3GHz, but I had to add some concentric tubes to the face opposite the tuning screws.
The filter looks like this:
https://g4cch.com/images/13cm/Evanescent_%20mode_filter/WG17/20210130_105850_1.jpg
https://g4cch.com//images/13cm/Evanescent_%20mode_filter/WG17/20210130_105911_1.jpg
The tuning screws and nuts came from some surplus Nokia filters the at I have.

This was a useful project to try out my nanovna v2 plus 4, the passband looks like this:
https://g4cch.com//images/13cm/Evanescent_%20mode_filter/WG17/20210130_111150_1.jpg

The filter is too narrow for my application, and it's too lossy.
As you say - it would be nice to get a filter that covers 2300 - 2420 with a good transition band.
Actually, I don't need to worry about image rejection, as I have a 7 pole filter on the 13cm side of the mixer.

The evanescent mode filter is intended to be placed between my G4DDK VLNA (at feed point) and the RF stage (mga86576) in my transverter.
This is part of an effort to reduce wifi qrm which I can see on 2320, and of course much worse on 2400.
I'm sure that the RF stage in the transverter is being overloaded, and tests using a pipecap filter proved that was the case, and the qrm could be eliminated.

In addition to the above, I changed the RF stage in the transverter to a PHA-83w, and this has almost eliminated the problem with out adding any extra filtering.
No qrm on 2320, 2300, 2304, 2301, and greatly reduced on 2400 (was S9 on K3S meter). I can now receive JA's again on 2400 EME.

Almost there, but would like to build another filter using the right waveguide this time.

Thanks and 73
Howard, G4CCH



Re: EVO Filter construction

Mark GM4ISM
 

I haven't looked yet for WG15, I probably have some short bits

I have reasonable amounts of WG14 though, if anyone wants some.

Mark GM4ISM


On 30/01/2021 10:30, John Fell wrote:
"Evanescent filters are so easy to throw together, and drilling too many tapped holes while just playing around .... ".

This from Mr "I don't do mechanical things "   LOL.

As Andy says WG16 does work well @ 13cm but needs some care as the setting screw to guide wall is very close .I too have made a few - Tip - add wingnuts and locknuts - it makes adjusting a lot easier .You do not need to close the guide ends , but if you do to keep insects etc out of the filter ,use adhesive backed copper tape .

73
John
G0API

Virus-free. www.avg.com


Re: Anyone got any spare WG15 / WR112 waveguide

g4cch_1
 
Edited

Thanks Andy, and I will take your advice...

I build stuff, and experiment, even though I don't always know what I am doing.
Eventually I get there, well most of the time...

So I am looking for WG14 (WR137), but will take WG15 (WR112) if anyone has any to spare.
I have some WG16, but not enough to waste, so may need some more of anyone has some to spare.

I built a filter using WG17 just because I had some, and used dimensions for this QEX article:
http://www.w1ghz.org/filter/QEX_Mar_2010_p23-29.pdf

I realised later that the WG17 was for a 5.7GHz filter.

Anyway, the filter did eventually tune down to 2.3GHz, but I had to add some concentric tubes to the face opposite the tuning screws.
The filter looks like this:
https://g4cch.com//images/13cm/Evanescent_%20mode_filter/WG17/20210130_105850_1.jpg

https://g4cch.com//images/13cm/Evanescent_%20mode_filter/WG17/20210130_105911_1.jpg

The tuning screws and nuts came from some surplus Nokia filters the at I have.

This was a useful project to try out my nanovna v2 plus 4, the passband looks like this:
https://g4cch.com//images/13cm/Evanescent_%20mode_filter/WG17/20210130_111150_1.jpg

The filter is too narrow for my application, and it's too lossy.
As you say - it would be nice to get a filter that covers 2300 - 2420 with a good transition band.
Actually, I don't need to worry about image rejection, as I have a 7 pole filter on the 13cm side of the mixer.

The evanescent mode filter is intended to be placed between my G4DDK VLNA (at feed point) and the RF stage (mga86576) in my transverter.
This is part of an effort to reduce wifi qrm which I can see on 2320, and of course much worse on 2400.
I'm sure that the RF stage in the transverter is being overloaded, and tests using a pipecap filter proved that was the case, and the qrm could be eliminated.

In addition to the above, I changed the RF stage in the transverter to a PHA-83w, and this has almost eliminated the problem with out adding any extra filtering.
No qrm on 2320, 2300, 2304, 2301, and greatly reduced on 2400 (was S9 on K3S meter). I can now receive JA's again on 2400 EME.

Almost there, but would like to build another filter using the right waveguide this time.

Thanks and 73
Howard, G4CCH



Re: round attenuator dissasembly?

alwyn.seeds1
 

Dear All,

The very common hazards in electronics are BeO thermal links and Beryllium Copper alloys used in spring stock and in RF vacuum device construction.

Eimac Varian used to include BeO hazard sheets with most of their valves and I remember long debates as to whether the insulating seals in 4CX250Bs were Beryllium Oxide- I think it was decided that they were not, though the thermal links of conduction cooled versions were. External anodes frequently used Beryllium Copper for better machining- machinists often suffered from lung disease, though it may have been incorrectly attributed to smoking.

Lots of RF power transistors from the 1960s to the 1980s used BeO packaging for better heat conductivity and RF attenuators/loads frequently deposit the resistive element on BeO, again for better heat conductivity.

So I would not dismantle a BeO containing device and would be careful cutting up old valves which may contain a variety of toxic substances as well as the Beryllium Copper hazard.

Those who worked in the manufacturers would know more.

Regards,

Alwyn G8DOH

   
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Re: DC switching.

Colin Ranson
 

I like ’real’ RF Andy, seems a shame to relegate the DDS to the bin.

 

Happy rainy days !

 

Colin.

 

Sent from Mail for Windows 10

 

From: Andy G4JNT
Sent: 30 January 2021 11:45
To: UK Microwaves groups.io
Subject: Re: [UKMicrowaves] DC switching.

 

Or use a synthesizer module...

 

Andy

 

 

 

On Sat, 30 Jan 2021 at 10:47, Colin Ranson <g8lbs@...> wrote:

All,

 

High Power DC 5V-36V 15A 400W MOSFET Trigger Switch Drive Module

High Power DC 5V-36V 15A 400W MOSFET Trigger Switch Drive Module

Total: £5.99 per pair.

Order number: 15-06479-48440

Item number: 133549042395

 

 

 

 

 

2 x modules arrived this morning.   Rather amused to see that the high current switching (with those blue screw down connectors ? )  is done in the NEGATIVE line !   Oh well, expect they will be useful for something.

 

I have ordered one of the French 10GHz PCB’s.    I knew I would build something one day with a UHF IF, funnily enough I have a couple of the mixers already in stock- premonition ? About 5 years ago I built a G4HUP DDS with an output of 92MHz. So just need to knuckle down and make a multiplier chain (x3, x3, x3.)

 

Regards to all,

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

 


Re: DC switching.

Andy G4JNT
 

Or use a synthesizer module...



On Sat, 30 Jan 2021 at 10:47, Colin Ranson <g8lbs@...> wrote:

All,

 

High Power DC 5V-36V 15A 400W MOSFET Trigger Switch Drive Module

High Power DC 5V-36V 15A 400W MOSFET Trigger Switch Drive Module

Total: £5.99 per pair.

Order number: 15-06479-48440

Item number: 133549042395

 

 

 

 

 

2 x modules arrived this morning.   Rather amused to see that the high current switching (with those blue screw down connectors ? )  is done in the NEGATIVE line !   Oh well, expect they will be useful for something.

 

I have ordered one of the French 10GHz PCB’s.    I knew I would build something one day with a UHF IF, funnily enough I have a couple of the mixers already in stock- premonition ? About 5 years ago I built a G4HUP DDS with an output of 92MHz. So just need to knuckle down and make a multiplier chain (x3, x3, x3.)

 

Regards to all,

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 


Re: EVO Filter construction

Andy G4JNT
 

WG16 at 9cm, not 13
Do like the wind nut idea

Drilling holes and tapping is about the limit of my metalworking skills



On Sat, 30 Jan 2021 at 10:30, John Fell <john.g0api@...> wrote:
"Evanescent filters are so easy to throw together, and drilling too many tapped holes while just playing around .... ".

This from Mr "I don't do mechanical things "   LOL.

As Andy says WG16 does work well @ 13cm but needs some care as the setting screw to guide wall is very close .I too have made a few - Tip - add wingnuts and locknuts - it makes adjusting a lot easier .You do not need to close the guide ends , but if you do to keep insects etc out of the filter ,use adhesive backed copper tape .

73
John
G0API


Re: DC switching.

Colin Ranson
 

Yo a star Robin !

 

Put me down for one please.

 

Thanks,

 

Colin G8LBS.         PS me and HWSBO have our jabs next Tuesday.

 

Sent from Mail for Windows 10

 

From: Robin Szemeti - G1YFG
Sent: 30 January 2021 10:53
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] DC switching.

 

Yep, that is what I was trying to tell you :) they are a "low side switch" .. they switch in the negative side.

 

Worry not, 25 high side switch boards are on their way ...

 

On Sat, 30 Jan 2021 at 10:47, Colin Ranson <g8lbs@...> wrote:

All,

 

High Power DC 5V-36V 15A 400W MOSFET Trigger Switch Drive Module

High Power DC 5V-36V 15A 400W MOSFET Trigger Switch Drive Module

Total: £5.99 per pair.

Order number: 15-06479-48440

Item number: 133549042395

 

 

 

 

 

2 x modules arrived this morning.   Rather amused to see that the high current switching (with those blue screw down connectors ? )  is done in the NEGATIVE line !   Oh well, expect they will be useful for something.

 

I have ordered one of the French 10GHz PCB’s.    I knew I would build something one day with a UHF IF, funnily enough I have a couple of the mixers already in stock- premonition ? About 5 years ago I built a G4HUP DDS with an output of 92MHz. So just need to knuckle down and make a multiplier chain (x3, x3, x3.)

 

Regards to all,

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 


--
Robin Szemeti - G1YFG

 


Re: DC switching.

Robin Szemeti - G1YFG
 

Yep, that is what I was trying to tell you :) they are a "low side switch" .. they switch in the negative side.

Worry not, 25 high side switch boards are on their way ...


On Sat, 30 Jan 2021 at 10:47, Colin Ranson <g8lbs@...> wrote:

All,

 

High Power DC 5V-36V 15A 400W MOSFET Trigger Switch Drive Module

High Power DC 5V-36V 15A 400W MOSFET Trigger Switch Drive Module

Total: £5.99 per pair.

Order number: 15-06479-48440

Item number: 133549042395

 

 

 

 

 

2 x modules arrived this morning.   Rather amused to see that the high current switching (with those blue screw down connectors ? )  is done in the NEGATIVE line !   Oh well, expect they will be useful for something.

 

I have ordered one of the French 10GHz PCB’s.    I knew I would build something one day with a UHF IF, funnily enough I have a couple of the mixers already in stock- premonition ? About 5 years ago I built a G4HUP DDS with an output of 92MHz. So just need to knuckle down and make a multiplier chain (x3, x3, x3.)

 

Regards to all,

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 


--
Robin Szemeti - G1YFG

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