Date   

Re: GHz Bands column input requested

Andrew M0CWX
 

How about a minimal working example receiver for 2.3GHz? Getting me an RX (of sorts) on 13 cms. 

Using cheap ADF4351 for LO on 1888 MHz;
homemade (yes that’s tinfoil and garden wire!) bi-quad;
mixer I got as junk at the Roundtable and 
an SDR dongle.

Not going to win a DX award but on the waterfall is GB3ZME 25 miles away from the antenna on the bench.

Best wishes,
Andrew
M0CWX
Halesowen
IO82XK







Re: 3D printed cassegrain reflector.

Colin G4EML
 

With todays slightly warmer weather I have been doing some initial tests outdoors with the 3d printed and copper plated cassegrain reflector and 18" Edmund dish on 122GHz. 
The results look very encouraging. Adjustment of the reflector shows a well defined peak in gain when the tip of the reflector is in line with the face of the dish. Which I think is what was intended in Neil's calculations. 
Adjustment of the feed horn does not seem to be anywhere near as critical, I have ended up with it protruding from the rear of the dish by about 5mm. 

This is giving me a Very sharp beam with only one well defined peak.  

My test source is just an RF Explorer signal generator at 4.9Ghz feeding about +10dBm into a diode soldered across the end of a short piece of semi rigid to generate the 25th Harmonic. I can detect this at about 20dB over the noise level a range of 10m.  I will try to do some comparison tests with other antennas later in the week if the weather stays OK. 

Colin G4EML





Re: Crystal detector?

Roger Ray
 

Thanks for all the input. That gives me a lot of information to allow me to sort out the meter scale.
Hopefully I will be able to make use of it soon.
Roger
G8CUB


On 17 Jan 2022, at 08:02, Dave G8KHU <david@...> wrote:

Hi Roger

There are several threads with useful information on the HP group, search "meter scales"

https://groups.io/g/HP-Agilent-Keysight-equipment

73 Dave


Re: G3WDG Filters for 2 mtr to 10GHz receiver

Andy MM0FMF
 

Dennis you can just download the info if you are keen to get moving.



I remembered right, the dimensions are in the instructions I received with my kits of parts all those years back. 😉

73
Andy





From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Dennis_G6YBC via groups.io <g6ybc@...>
Sent: Monday, January 17, 2022 7:41 AM
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] G3WDG Filters for 2 mtr to 10GHz receiver
 
Thanks you to all (to many to mention here) that have replied with the various information and diagram of the filter. 

I have DM’d Steve hopefully he still has the original, if not thanks for the diagram to make own. Someone has said I can loan the Manual Vol 3. 

Many thanks again

Dennis G6YBC 





Re: G3WDG Filters for 2 mtr to 10GHz receiver

Dennis_G6YBC
 

Thanks you to all (to many to mention here) that have replied with the various information and diagram of the filter. 

I have DM’d Steve hopefully he still has the original, if not thanks for the diagram to make own. Someone has said I can loan the Manual Vol 3. 

Many thanks again

Dennis G6YBC 





Re: G4BAO Driver kits update

John Worsnop
 

Seems that the PD85004 device I use is now listed as obsolete and no longer manufactured, so  I have ordered a few of a different device to try in the board.

Watch this space 

73
John


On Sun, 16 Jan 2022 at 17:37, g4bao <john@...> wrote:
Just checked the RS website and the LDMOS devices that these boards use, that I've had on order since 13th April 2021, have been pushed out again to 14th April of this year....

Sigh.....

73
John


Re: GHz Bands column input requested

g4bao
 

Thanks for all the great input so far! Seems it's not such a quiet time after all!
Keep it coming as anything that misses the RadCom deadline will get in to the Scatterpoint Activity report that I'll be working on next/
Here I've been down the rabbit hole of repairing a dodgy Windows PC for almost 2 weeks now followed by a Win 11 update (which went without a hitch BTW!)
All my ancient radio apps seem to work on the the new Motherboard and OS, so just the final backups to do and I can get back to radio projects including finishing the software for the 24GHz EME TWT controller.

73 All
Hope we get to meet face to face again soon, its been so long there are now active people on the reflector I've not met!!

John 


Re: G3WDG 144 MHz to 10 GHz Transverter

Colin G4EML
 

Hi Julian. 

I would suggest you have a listen for the Reigate Hill beacon GB3SEE on 10368.850. That should be a good signal from North London. 
I can also go out to the North Downs at IO91SF if you want to do a test. 
It looks like both are line of sight to Mill Hill. 

Colin G4EML. 




On 17 Jan 2022, at 12:07, g4zod@... via groups.io <g4zod@...> wrote:

Over twenty years ago I built the above Transverter and it was tested at Martlesham Round Table.
It has a Small dish on the output with a penny feed.
(It has been in dry storage with my 13 CMs Transverter ever since.)
I recently found a high spot in Mill Hill , NW London and I get a clear view between Canary wharf and Wembley.
Is there anyone to South I could possibly set up a QSO with?
I think I have 1 Watt output ,but I cannot check it as I lent my power meter to someone and he has since vanished with it.
Julian
G4ZOD

Sent from BlueMail


Re: GHz Bands column input requested

Denis Stanton G0OLX
 

Hi John
Having seen Peters reply
I am also now have EME TX capabilities and have so far made 5 contacts in 5 countries using Q65 60 D or E
Using a standard 1.2 metre offset dish and standard SPID RAS. 1 degree rotator mounted at 2.4 metres above ground which keeps the near field above people heads to meet the new Ofcom field strength standards!!!!!!
Kuhne Coaxial low noise preamp and a 22 Watt SSPA giving 15 Watts allowing for ferrite isolator, coaxial relay and leads and connectors
Feed is I0JXX, Sun noise is not brilliant 4 to 5 dB on a good day and moon noise about 0.2 dB
Finding the moon without the DL0SHF beacon is difficult but not impossible as most of contacts have been without the moon beacon which by the way is suffering from an Az El problem according to Per who is unable to fix due to bad weather conditions on site
Hope that may fill a few lines for you best 73
Denis
G0OLX


Kuhne G3 transverter

On 17 Jan 2022, at 11:27, Barry Chambers <b.chambers@...> wrote:

GM John

I have been doing some 122GHz tests with G0EWN and G4APV; best dx so far is 12km. More signal is in hand but initial dish alignment in bright sunlight is the problem at present. We have been using red light boxes as alignment aids but need bigger lenses in front of the Phlatlights so will have to dig out the old red light rigs which G0EWN and I still have from the "old days"!

As a diversion, I am also looking at fitting a QRSS1/3 decoder into my 30THz receivers as recording such slow cw by hand is very tedious. Yes, I know about PC software to read QRSS but want the 30THz system to be portable. The 30THz Rxs already have signal detection so a QRSS decoder only needs a software few timers and a buffer since it can also use the existing Rx LCD display.

73

Barry, G8AGN







G3WDG 144 MHz to 10 GHz Transverter

g4zod@btinternet.com
 

Over twenty years ago I built the above Transverter and it was tested at Martlesham Round Table.
It has a Small dish on the output with a penny feed.
(It has been in dry storage with my 13 CMs Transverter ever since.)
I recently found a high spot in Mill Hill , NW London and I get a clear view between Canary wharf and Wembley.
Is there anyone to South I could possibly set up a QSO with?
I think I have 1 Watt output ,but I cannot check it as I lent my power meter to someone and he has since vanished with it.
Julian
G4ZOD

Sent from BlueMail


Re: G3WDG Filters for 2 mtr to 10GHz receiver

SAM JEWELL
 

The original pipe caps for the original G3WDG transverter and 001 multiplier were made by Cyril, G3VVB, in his workshop in the west country. We managed to find someone (apologies, forgotten the callsign but lived in the Midlands) to silver plate them for next to no cost. Between them they must have made dozens of 'filters'. I recall that Mike then volunteered to make them when Cyril was no longer able to for health reasons.

73 de Sam, G4DDK



On 17 Jan 2022, at 10:49, Michael Scott via groups.io <g3lyp@...> wrote:



They were made from 3/4 inch brass rod, I know because I made several hundred for Charlie. Initially, I sent them for silver plating, but later on Charlie found that this was not necessary. The need dried up when people found that 1/2 inch copper pipe caps ( Stop ends in the UK ) worked as well.

73, Mike, G3LYP.


On 17/01/2022 09:08, Andy wrote:

Maybe a dumb question but are the sizes not in the instructions?  I remember there was a section about how to cut and mount the probes that solder to the PCB.  I'm fairly sure they'll be a standard pipe cap size and the top was drilled and tapped for an M4 tuning screw with lock nut.


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Dennis_G6YBC via groups.io <g6ybc@...>
Sent: Monday, January 17, 2022 12:59 AM
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] G3WDG Filters for 2 mtr to 10GHz receiver
 
Hi Robin 

Sadly no,  I have the kit but these are missing so
was hoping someone here would have an idea of what I mean. 

Regards 

Dennis G6YBC 



Re: GHz Bands column input requested

Barry Chambers
 

GM John

I have been  doing some 122GHz tests with G0EWN and G4APV; best dx so far is 12km. More signal is in hand but initial dish alignment in bright sunlight is the problem at present. We have been using red light boxes as alignment aids but need bigger lenses in front of the Phlatlights so will have to dig out the old red light rigs which G0EWN and I still have from the "old days"!

As a diversion, I am also looking at fitting a QRSS1/3 decoder into my 30THz receivers as recording such slow cw by hand is very tedious. Yes, I know about PC software to read QRSS but want the 30THz system to be portable. The 30THz Rxs already have signal detection so a QRSS decoder only needs a software few timers and a buffer since it can also use the existing Rx LCD display.

73

Barry, G8AGN


Re: GHz Bands column input requested

SAM JEWELL
 

The Martlesham Organisers are looking at a possible one day event for 2022. Details will be announced when firmer arrangements have been made.
Hope to see lots of you there.

Sam, G4DDK


On 17 Jan 2022, at 10:42, David Hilton-Jones via groups.io <g4ytl@...> wrote:



Hi John

 

A fallow time of year!

 

Making progress on 3cm EME – now 21# and 13 DXCC

 

Slowly building a system for 3cm tropo/rain scatter from home – will be a 60cm dish and 3 watts output. Hope to be QRV by February.

 

Managed to find a power meter and sensor head at reasonable price – HP437B and HP8481A head (-30dbm to 20dbm)

 

Do you know if Martlesham will go ahead this year?

 

 

Unrelated to column, I will send you an email I recently received from PA3DZL – might be of interest.

 

73

 

 

David, G4YTL

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of g4bao
Sent: 16 January 2022 18:57
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] GHz Bands column input requested

 

Hi All

Its that time of year when it's hard to find much interesting going on that makes good column inches, so I'd appreciate any news or Tech Snippets etc by Wednesday at the latest please.

Otherwise It'll be another "Fen Edge Soapbox" and we don't want that, do we? ! :-)  

Someone must have done something remarkable, but I have to admit I haven't .....

:-)

73

John


KST2ME demise

Robin Szemeti - G1YFG
 

As some of you may have heard, the author of KST2ME, Bo, has said that no more license keys will be issued,  once your current key expires, it is dead.

If anyone has any specific features of KST2ME that they would dearly love to have included in my web-based alternative, if you could let me know by PM, ideally with a screenshot,  I'll try and at least consider them.

There is a write-up of my web thing here, if anyone is unfamiliar.


--
Best regards,

Robin Szemeti, G1YFG

--
Robin Szemeti - G1YFG


Re: G3WDG Filters for 2 mtr to 10GHz receiver

Michael Scott
 

They were made from 3/4 inch brass rod, I know because I made several hundred for Charlie. Initially, I sent them for silver plating, but later on Charlie found that this was not necessary. The need dried up when people found that 1/2 inch copper pipe caps ( Stop ends in the UK ) worked as well.

73, Mike, G3LYP.


On 17/01/2022 09:08, Andy wrote:

Maybe a dumb question but are the sizes not in the instructions?  I remember there was a section about how to cut and mount the probes that solder to the PCB.  I'm fairly sure they'll be a standard pipe cap size and the top was drilled and tapped for an M4 tuning screw with lock nut.


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Dennis_G6YBC via groups.io <g6ybc@...>
Sent: Monday, January 17, 2022 12:59 AM
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] G3WDG Filters for 2 mtr to 10GHz receiver
 
Hi Robin 

Sadly no,  I have the kit but these are missing so
was hoping someone here would have an idea of what I mean. 

Regards 

Dennis G6YBC 



Re: GHz Bands column input requested

Robin Szemeti - G1YFG
 

Hi John, I've been blogging various bits of "stuff" at https://g1yfg.blogspot.com/ but nothing really complete yet. I hope to complete the final verison of the 13cm LNA at some point which may then make enough for an article ...

On Sun, 16 Jan 2022 at 18:57, g4bao <john@...> wrote:
Hi All

Its that time of year when it's hard to find much interesting going on that makes good column inches, so I'd appreciate any news or Tech Snippets etc by Wednesday at the latest please.

Otherwise It'll be another "Fen Edge Soapbox" and we don't want that, do we? ! :-)  

Someone must have done something remarkable, but I have to admit I haven't .....

:-)

73

John


--
Robin Szemeti - G1YFG


Re: GHz Bands column input requested

David Hilton-Jones
 

Hi John

 

A fallow time of year!

 

Making progress on 3cm EME – now 21# and 13 DXCC

 

Slowly building a system for 3cm tropo/rain scatter from home – will be a 60cm dish and 3 watts output. Hope to be QRV by February.

 

Managed to find a power meter and sensor head at reasonable price – HP437B and HP8481A head (-30dbm to 20dbm)

 

Do you know if Martlesham will go ahead this year?

 

 

Unrelated to column, I will send you an email I recently received from PA3DZL – might be of interest.

 

73

 

 

David, G4YTL

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of g4bao
Sent: 16 January 2022 18:57
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] GHz Bands column input requested

 

Hi All

Its that time of year when it's hard to find much interesting going on that makes good column inches, so I'd appreciate any news or Tech Snippets etc by Wednesday at the latest please.

Otherwise It'll be another "Fen Edge Soapbox" and we don't want that, do we? ! :-)  

Someone must have done something remarkable, but I have to admit I haven't .....

:-)

73

John


Re: G3WDG Filters for 2 mtr to 10GHz receiver

Gerhard_DK4XP
 

Hi,

https://wiki.microwavers.org.uk/G3WDG_Microwave_Designs    >

has the complete description.
You should try if you get by with pipe end caps. The tuning range is huge
and you can see what you get without soldering the cap. Slight pressure
is enough.

Last summer, I have made some measurements, too.
But my VNA works only to 8 GHz.
www.hoffmann-hochfrequenz.de/downloads/PipeCapFilters.pdf
>

Regards 

Gerhard DK4XP


Re: G3WDG Filters for 2 mtr to 10GHz receiver

Paul G8AQA
 

Brass would need to be silver plated in view of the poor conductivity of brass.
15 mm copper pipe caps adjusted to the required length should be quite adequate.  Pipe cap filters can be tuned over quite a range.

If you have a pipe expander you could increase the internal diameter to 16mm. I doubt whether this would be necessary.

If you use a BA screw rather than an ISO Metric you will get a slightly finer adjustment and better thread contact. The contact angle is 47.5 degrees rather than 60 degrees.

73
Paul G8AQA

On 17/01/2022 09:45, Chris G8BKE wrote:
The dimensions are in the Microwave Handbook Vol 3 ...see attached

73


Virus-free. www.avg.com


Re: G3WDG Filters for 2 mtr to 10GHz receiver

Robin Szemeti - G1YFG
 

I could turn you some up in brass ... sadly I can no longer silver plate as the fish tank full of cyanide has been deemed to be one the "you're not bringing that thing in the car" items that didn't make it through the last workshop move.  How many were you after?

On Mon, 17 Jan 2022 at 09:45, Chris G8BKE <berryway21@...> wrote:
The dimensions are in the Microwave Handbook Vol 3 ...see attached

73


--
Robin Szemeti - G1YFG

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