Date   

GB3PKT 10 Ghz Beacon

david656179
 

Can somebody confirm that GB3PKT is on air please.  It is always a good signal here in JO02, albeit scattered at times.

Thanks



Re: DB6NT sequencer

Robin Szemeti - G1YFG
 

Daft question ... have you got a back EMF diode on the relay coil?  You need something to catch the pulse when FET opens and the coil current collapses.  You could try slowing the gate rase/fall times to limit the di/dt in the coil.

On Tue, 23 Mar 2021 at 10:20, Graham - G3YJR <g3yjr@...> wrote:
I wonder if you might have done this?: I put an indicator LED/resistor across the switching FET to indicate the state and I was surprised to find that the indicator LED passed just enough current to hold the relay on. A higher resistance and a lower-drain/brighter LED solved the problem.

73 Graham


--
Robin Szemeti - G1YFG


30THz experiments ...video

G3PHO - Peter
 

Barry, G8AGN, asked me to collate his video clips of his except experiments on 30THz. You can find them on You Tube at this link:


https://youtu.be/jZ_lQgRyC5c

Any one for “heatwaves” ?  :-)

Peter G3PHO


Re: DB6NT sequencer

Graham - G3YJR
 

I wonder if you might have done this?: I put an indicator LED/resistor across the switching FET to indicate the state and I was surprised to find that the indicator LED passed just enough current to hold the relay on. A higher resistance and a lower-drain/brighter LED solved the problem.

73 Graham


Re: Wavelab 2W 24Ghz TRV

Robin Szemeti - G1YFG
 

Very nice! ...

One thought, the -5V is very important ... and on J4 and J7 there are two pins on each connector for this ... it would be possible to send the -5 to the board  on on pin say J4 pin 9,  and use pin 10 as a "safety circuit" ...  same for J7 pins 17, 18 ... send the -5 on one pin, bring it back to the PSU board from the other pin for detection ...   now you can know not only is the -5 correctly generated on the PSU board, but the wiring and connectors are all good also ... 2 safety circuits for the -5V directly from the module?


On Mon, 22 Mar 2021 at 21:57, Marek Rejf <sp4elf@...> wrote:
Hello
The power supply for the Wavelab  24GHz trv module has been launched.
More information soon on the forum " http://mikrofale.cafe/showthread.php?tid=197&pid=698#pid698 " .

Diagram of the power module

 



73 Marek SP4ELF


--
Robin Szemeti - G1YFG


Re: Wavelab 2W 24Ghz TRV

Marek Rejf
 

Hello
The power supply for the Wavelab  24GHz trv module has been launched.
More information soon on the forum " http://mikrofale.cafe/showthread.php?tid=197&pid=698#pid698 " .

Diagram of the power module

 



73 Marek SP4ELF


Re: 10 MHz Reference Distribution Amplifier

Tim Hague M0AFJ
 

That is what I have done with my Leo Bodnar GPSDO and my 4 transverters and counter. Works fine

Best Regards
Tim Hague M0AFJ


On 22 Mar 2021, at 19:13, Greg - ZL3IX <zl3ix@...> wrote:

Depending on the input impedance of your client devices, and how many of them you have, you could try daisy chaining them using BNC Tee pieces, with a 50 ohm termination at the far end. This is done successfully with up to 8 devices (all with Hi-Z inputs) on some professional radio sites.


Re: 10 MHz Reference Distribution Amplifier

Greg - ZL3IX
 

Depending on the input impedance of your client devices, and how many of them you have, you could try daisy chaining them using BNC Tee pieces, with a 50 ohm termination at the far end. This is done successfully with up to 8 devices (all with Hi-Z inputs) on some professional radio sites.


Re: OZ8AFC 8.4 GHz Feedhorn with adjustable Scalar Rings

Keith
 

Hi Ole,
well one is on its way to my " shelf" as we speak :)
It is made for 8.5 Ghz which is where I intend to use it, but I can find very little about them. 
All I really want to know is the f/d range it will most likely cover.
Many thanks 
73
Keith


Re: OZ8AFC 8.4 GHz Feedhorn with adjustable Scalar Rings

Alan
 

Hi Keith,

I still use one of Palle's offset 3cm horns - Sadly he died in a car crash I think almost 10 years ago quite soon after I bought it.

73 Alan GM0USI/P



07785744643

info@...

www.alandimmick.com

instagram @alandimmick

Studio 331

60-64 Osborne St

South Block

Glasgow

G1 5QH






From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Keith <Keith@...>
Sent: 22 March 2021 05:45
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: [UKMicrowaves] OZ8AFC 8.4 GHz Feedhorn with adjustable Scalar Rings
 
Is anyone familiar with the above feed please ?
Information is very limited as apparently they were made to order and frequency. 
I assume there would have been versions for 10 ghz so thought I'd ask here.
Any info appreciated and hopefully pics attached.
73
Keith


Re: OZ8AFC 8.4 GHz Feedhorn with adjustable Scalar Rings

Ole OZ2OE
 

Hi Keith

OZ8AFC (SK) produced feedhorns for 5,7GHz, 8,4GHz, 10 GHz and combi 10/24 GHz. After his untimely death OZ9ZZ and I acquired the stock of unfinished parts and started assembling/finishing feedhorns. The revenue from sales has been used for operating the OZ5SHF beacon system.

All feeds are long gone - although I guess a good part ended up on shelves.

73 Ole OZ2OE


 

Den 22. marts 2021 kl. 06.45.52 +01.00, skrev Keith <Keith@...>:

Is anyone familiar with the above feed please ?
Information is very limited as apparently they were made to order and frequency. 
I assume there would have been versions for 10 ghz so thought I'd ask here.
Any info appreciated and hopefully pics attached.
73
Keith


Re: Dmm switch contacts ...........

Gordon REASON <gordonj.reason@...>
 

Thankyou Phil .....I'l see what I can do ........

On 21 March 2021 at 22:32 Phil Guttridge G3TCU <p.guttridge@...> wrote:

I have a couple of scrap DMMs Gordon, if you have other contacts like the one you need to replace, could you send me a pic?

73, Phil G3TCU

On 21/03/2021 22:26, Gordon REASON via groups.io wrote:

Trying to mod my cheap dmm for a louder sounder , and I've lost a rotary switch sprung contact ......

They seem impossible to obtain , but do any of you genious'es on ere , know of a source .......

Trying to make some , but it's hit and miss !

Thanks .



Virus-free. www.avg.com


 


 


OZ8AFC 8.4 GHz Feedhorn with adjustable Scalar Rings

Keith
 

Is anyone familiar with the above feed please ?
Information is very limited as apparently they were made to order and frequency. 
I assume there would have been versions for 10 ghz so thought I'd ask here.
Any info appreciated and hopefully pics attached.
73
Keith


Re: Dmm switch contacts ...........

Phil Guttridge G3TCU
 

I have a couple of scrap DMMs Gordon, if you have other contacts like the one you need to replace, could you send me a pic?

73, Phil G3TCU

On 21/03/2021 22:26, Gordon REASON via groups.io wrote:

Trying to mod my cheap dmm for a louder sounder , and I've lost a rotary switch sprung contact ......

They seem impossible to obtain , but do any of you genious'es on ere , know of a source .......

Trying to make some , but it's hit and miss !

Thanks .


Virus-free. www.avg.com


Dmm switch contacts ...........

Gordon REASON <gordonj.reason@...>
 

Trying to mod my cheap dmm for a louder sounder , and I've lost a rotary switch sprung contact ......

They seem impossible to obtain , but do any of you genious'es on ere , know of a source .......

Trying to make some , but it's hit and miss !

Thanks .


Re: 10 MHz Reference Distribution Amplifier

Stephen Tompsett
 

I use very similar 8 port units for distribution of 10MHz to the radio equipment (transceivers and transverters)...

I used the TAPR TADD-1 (https://tapr.org/product/tadd-1-rf-distribution-amplifier/) in my main frequency reference system for distributing the signal to test equipment - nice but considerably more expensive...

On 21/03/2021 16:55, Norman Stewart via groups.io wrote:
Anyone had success with either of these or similar items for distributing a 10 MHz reference signal to multiple equipment?

LiNKFOR SDI Splitter 1 x 4 with Certified Power Adapter: Amazon.co.uk: Electronics

#N/A 4 Way BNC Composite Video Splitter BNC Interface: Amazon.co.uk: Electronics

73
--
Norman Stewart GM1CNH
-- 
Stephen Tompsett (G8LYB)
Tel: 01788 578940
Mob: 07956 855816


Re: 10 MHz Reference Distribution Amplifier

DD1US
 

Hi Dave,

 

very nice.

 

Based on your design here is another option including output transformers:

 

http://www.dd1us.de/Downloads/10%20MHz%20distribution%20unit%20with%204%20isolated%20outputs%20v3.pdf

 

Marek, SP4ELF, a good friend of mine made the layout.

 

Kind regards

 

Matthias

 

www.dd1us.de

 

 

Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io> Im Auftrag von David Robinson
Gesendet: Sonntag, 21. März 2021 21:17
An: UKMicrowaves@groups.io
Betreff: Re: [UKMicrowaves] 10 MHz Reference Distribution Amplifier

 

Thats the one I use. i even did a pcb for it (without the doubler) Have four 4 ways in use currently

http://g4fre.com/10MHz_distribution.htm

Dave
G4FRE

I built one using high speed op-amps


Re: 10 MHz Reference Distribution Amplifier

David Robinson
 

Thats the one I use. i even did a pcb for it (without the doubler) Have four 4 ways in use currently

http://g4fre.com/10MHz_distribution.htm

Dave
G4FRE

I built one using high speed op-amps


Re: 10 MHz Reference Distribution Amplifier

 

On Sun, 21 Mar 2021 at 18:55, Andy G4JNT <andy.g4jnt@...> wrote:
I built one using high speed op-amps



Time nuts would say you built a temperature sensor with that filter.

Dave


Re: 10 MHz Reference Distribution Amplifier

Colin Ranson
 

Hi Neil,

 

I stopped using my HUP Dist-amp because of just that and also plugging something in altered the output level on the others, I never bothered to find out why.  Until recently I have been using the Mini-Circuits splitter to feed my 23/13/9cm SG-Labs transverters.....(mine are stable enough without, it was just because I could)......   until I found my Chinese GPS has gone boobs up and was just outputting the OCXO frequency even though the LED said it was locked – it was just the RX acquiring the Sats.   I have now resurrected my G3RUH box - seems to be behaving ok – got to do the ‘locked’ LED mod.

 

As an aside – do you know the input impedance at 10MHz for the Dieter LO unit please ?

 

Best regards de G8LBS.

 

Sent from Mail for Windows 10

 

From: Neil Smith G4DBN
Sent: 21 March 2021 19:28
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] 10 MHz Reference Distribution Amplifier

 

I have some of Dave's units, and I've tried a few others, but always seem to hit a problem with inter-port crosstalk and noisy instruments polluting the reference though poor rejection of signals going into the outputs.  Some of that is caused by noise on the outer of the BNC connectors from power supply currents and earth returns going through the coax into the reference box instead of all through the proper returns.  For anything critical, I now use isolation transformers and shielded twisted pair to distribute the reference signals.  The effects are tiny, but if you have a raging SMPS moving tens of amps around, it doesn't take much current going along the coax brais to the distribution amp and back to the supply ground to modulate other outputs to the point where the reference starts producing spurs at the -80dBc level.

I did consider using fibre to distribute the reference, but there's a lot more places where noise and jitter and crosstalk show up. Nice shielded passive baluns and balanced amplifiers with excellent reverse attenuation is my go-to solution for now.

Neil G4DBN

 

On 21/03/2021 18:25, Colin Ranson wrote:

At 10 MHzI have used the G4HUP Distribution amplifier in the past and now I use a Mini-circuits ZFSC splitter, unused SMA outputs  terminated with 50ohm.

 

De G8LBS.

 

Sent from Mail for Windows 10

 

From: Jules - M0UGA
Sent: 21 March 2021 18:07
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] 10 MHz Reference Distribution Amplifier

 

SV1AFN also does a nice one. Just like everything from him it's beautifully made although not necessarily the cheapest.

www.sv1afn.com

www.sv1afn.com/en/gnss-gps/10-mhz-distribution-amplifier.html

 

 

 

2381 - 2400 of 64006