Date   

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

 

 

 


Re: 10 MHz Reference Distribution Amplifier

Neil Smith G4DBN
 

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

 



Re: 10 MHz Reference Distribution Amplifier

Colin Ranson
 

Nice !

 

De G8LBS.

 

Sent from Mail for Windows 10

 

From: Andy G4JNT
Sent: 21 March 2021 18:55
To: UK Microwaves groups.io
Subject: Re: [UKMicrowaves] 10 MHz Reference Distribution Amplifier

 

I built one using high speed op-amps

 

 

Andy

 

 

 

On Sun, 21 Mar 2021 at 18:26, Colin Ranson <g8lbs@...> 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

 

 


Re: 10 MHz Reference Distribution Amplifier

Andy G4JNT
 

I built one using high speed op-amps




On Sun, 21 Mar 2021 at 18:26, Colin Ranson <g8lbs@...> 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

 


Re: 10 MHz Reference Distribution Amplifier

Colin Ranson
 

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

 


Re: Original NanoVNA a waste of money

geoffrey pike
 

THe SAA-2 is very different
Geoff
GI0GDP

On Sunday, 21 March 2021, 16:41:35 GMT, Andy G4JNT <andy.g4jnt@...> wrote:


I've had a DG8SAQ VWNA for a long time, now, which in terms of performance, quality of software, display capability and user interface knocks spots off these Chinese things.   Its a really professional quality bit of kit and would normally be the only one I'd ever use.   In use, it's as nice to use as the HP ones I used to use at work - just doesn't go nearly as high in frequency :-(

But it needs a PC attached, so when out in the garden or up a mast (!) a small self contained one has more than a few advantages.

These Chinese Mini VNWAs are a blatant rip-off of the DG8SAQ, that uses exactly the same hardware, NE602/612 mixers that conveniently have a differential input so perfect for taking the output from a resistive bridge right down to DC.  



On Sun, 21 Mar 2021 at 16:27, G8DQX list <list@...> wrote:

Andy,

the block diagram and circuit (schematic) diagram are at https://github.com/ttrftech/NanoVNA/blob/master/doc/nanovna-blockdiagram.png. What brings the machine alive, though, is the firmware, which has had considerable development over time.

There are occasional reports on the nanoVNA list (https://groups.io/g/nanovna-users) of touch screens failing due to cases fouling the surface. The usual solution seems to be to add washers or shims. One also has a vague recollection of solder splashes being a problem.

HTH, 73, Stay Safe,

Robin, G8DQX

On 21/03/2021 13:04, Andy G4JNT wrote:
Update.
I removed front ang back covers, and it started to - sort of - work.  The touch screen is a total failure, but I can drive it using the manual button thing.  replaced the covers and it stayed working.    SO I'm guessing an intermittent in a ribbon cable link on the touchscreen.
SO it has been saved from the sledgehammer for now.

Also took the opportunity to look inside, including lifting the covers over the RF portion. Pretty boring; three NE602 mixer chips, something that is obviously a soundcard type interface chip and one that is probably an Si family synth  - although the number was a bit meaningless.



Re: 10 MHz Reference Distribution Amplifier

Jules - M0UGA
 

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


Re: 10 MHz Reference Distribution Amplifier

Dave (G1OGY)
 

Wouldn't touch 'em.

You could do worse than taking a look at DF9NP's offerings.
4-way and 10-way (built) boards that once you've got it in a box will run
off your shack PSU without recourse to strange wall warts or unusual voltages.
<http://www.df9np.de/page4.html> (scroll down)

Dave, G1OGY


Dave, G1OGY


On Sun, 21 Mar 2021 at 16:56, Norman Stewart via groups.io
<jacobite=btinternet.com@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


Re: 10 MHz Reference Distribution Amplifier

Alan Melia
 


At the bottom of the Amazon item in the notes it says ''not suitable for RF'' !!
 
Alan
G3NYK

----- Original Message -----
From: Andy G4JNT
Sent: Sunday, March 21, 2021 5:19 PM
Subject: Re: [UKMicrowaves] 10 MHz Reference Distribution Amplifier

AH. didn't spot the second line for the analogue splitter.   It's a lot cheaper too



On Sun, 21 Mar 2021 at 17:15, Robin Szemeti - G1YFG <robin@...> wrote:
" As they are splitters for digital signals"  Umm ... the "composite video" ones are analogue, very analogue, unity gain.  In theory they will be 75 Ohm ... whether they go up to 10MHz no clue, composite video only normally goes up to 5MHz, but composite video is very much a plain old analogue thing, not a digital thing.

On Sun, 21 Mar 2021 at 17:03, Andy G4JNT <andy.g4jnt@...> wrote:
As they are splitters for digital signals, I'd imagine they regenerate and do all sort of things with the input.  All you want for 10MHz is a split with some linear gain.

(Had to Google SDi to find what it was, tho.)




On Sun, 21 Mar 2021 at 16:56, Norman Stewart via groups.io <jacobite=btinternet.com@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


--
Robin Szemeti - G1YFG


Re: 10 MHz Reference Distribution Amplifier

Andy G4JNT
 

AH. didn't spot the second line for the analogue splitter.   It's a lot cheaper too



On Sun, 21 Mar 2021 at 17:15, Robin Szemeti - G1YFG <robin@...> wrote:
" As they are splitters for digital signals"  Umm ... the "composite video" ones are analogue, very analogue, unity gain.  In theory they will be 75 Ohm ... whether they go up to 10MHz no clue, composite video only normally goes up to 5MHz, but composite video is very much a plain old analogue thing, not a digital thing.

On Sun, 21 Mar 2021 at 17:03, Andy G4JNT <andy.g4jnt@...> wrote:
As they are splitters for digital signals, I'd imagine they regenerate and do all sort of things with the input.  All you want for 10MHz is a split with some linear gain.

(Had to Google SDi to find what it was, tho.)




On Sun, 21 Mar 2021 at 16:56, Norman Stewart via groups.io <jacobite=btinternet.com@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


--
Robin Szemeti - G1YFG


Re: 10 MHz Reference Distribution Amplifier

John Lemay
 

There’s also 4 and 10 way buffers from DF9NP:-

 

http://www.df9np.de/page4.html

 

Happy with mine.

 

John G4ZTR

 

 

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of ian hope (2E0IJH)
Sent: 21 March 2021 17:04
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] 10 MHz Reference Distribution Amplifier

 

I use one of these, https://www.ebay.co.uk/itm/10Mhz-OCXO-Benchmark-Frequency-Divider-8-Port-Output-Distribution-Amplifier/303909976834?hash=item46c2723b02:g:Ua4AAOSw4BVgQuyt

 

Ian

M5IJH

 

 

Sent: Sunday, March 21, 2021 at 4:55 PM
From: "Norman Stewart via groups.io" <jacobite@...>
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] 10 MHz Reference Distribution Amplifier

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


Re: 10 MHz Reference Distribution Amplifier

Robin Szemeti - G1YFG
 

" As they are splitters for digital signals"  Umm ... the "composite video" ones are analogue, very analogue, unity gain.  In theory they will be 75 Ohm ... whether they go up to 10MHz no clue, composite video only normally goes up to 5MHz, but composite video is very much a plain old analogue thing, not a digital thing.

On Sun, 21 Mar 2021 at 17:03, Andy G4JNT <andy.g4jnt@...> wrote:
As they are splitters for digital signals, I'd imagine they regenerate and do all sort of things with the input.  All you want for 10MHz is a split with some linear gain.

(Had to Google SDi to find what it was, tho.)




On Sun, 21 Mar 2021 at 16:56, Norman Stewart via groups.io <jacobite=btinternet.com@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


--
Robin Szemeti - G1YFG


Re: 10 MHz Reference Distribution Amplifier

ian hope (2E0IJH)
 

I use one of these, https://www.ebay.co.uk/itm/10Mhz-OCXO-Benchmark-Frequency-Divider-8-Port-Output-Distribution-Amplifier/303909976834?hash=item46c2723b02:g:Ua4AAOSw4BVgQuyt
 
Ian
M5IJH

 
 
Sent: Sunday, March 21, 2021 at 4:55 PM
From: "Norman Stewart via groups.io" <jacobite@...>
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] 10 MHz Reference Distribution Amplifier
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


Re: 10 MHz Reference Distribution Amplifier

Andy G4JNT
 

As they are splitters for digital signals, I'd imagine they regenerate and do all sort of things with the input.  All you want for 10MHz is a split with some linear gain.

(Had to Google SDi to find what it was, tho.)




On Sun, 21 Mar 2021 at 16:56, Norman Stewart via groups.io <jacobite=btinternet.com@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


10 MHz Reference Distribution Amplifier

Norman Stewart
 

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


Re: Original NanoVNA a waste of money

Andy G4JNT
 

I've had a DG8SAQ VWNA for a long time, now, which in terms of performance, quality of software, display capability and user interface knocks spots off these Chinese things.   Its a really professional quality bit of kit and would normally be the only one I'd ever use.   In use, it's as nice to use as the HP ones I used to use at work - just doesn't go nearly as high in frequency :-(

But it needs a PC attached, so when out in the garden or up a mast (!) a small self contained one has more than a few advantages.

These Chinese Mini VNWAs are a blatant rip-off of the DG8SAQ, that uses exactly the same hardware, NE602/612 mixers that conveniently have a differential input so perfect for taking the output from a resistive bridge right down to DC.  



On Sun, 21 Mar 2021 at 16:27, G8DQX list <list@...> wrote:

Andy,

the block diagram and circuit (schematic) diagram are at https://github.com/ttrftech/NanoVNA/blob/master/doc/nanovna-blockdiagram.png. What brings the machine alive, though, is the firmware, which has had considerable development over time.

There are occasional reports on the nanoVNA list (https://groups.io/g/nanovna-users) of touch screens failing due to cases fouling the surface. The usual solution seems to be to add washers or shims. One also has a vague recollection of solder splashes being a problem.

HTH, 73, Stay Safe,

Robin, G8DQX

On 21/03/2021 13:04, Andy G4JNT wrote:
Update.
I removed front ang back covers, and it started to - sort of - work.  The touch screen is a total failure, but I can drive it using the manual button thing.  replaced the covers and it stayed working.    SO I'm guessing an intermittent in a ribbon cable link on the touchscreen.
SO it has been saved from the sledgehammer for now.

Also took the opportunity to look inside, including lifting the covers over the RF portion. Pretty boring; three NE602 mixer chips, something that is obviously a soundcard type interface chip and one that is probably an Si family synth  - although the number was a bit meaningless.



Re: Original NanoVNA a waste of money

G8DQX list
 

Andy,

the block diagram and circuit (schematic) diagram are at https://github.com/ttrftech/NanoVNA/blob/master/doc/nanovna-blockdiagram.png. What brings the machine alive, though, is the firmware, which has had considerable development over time.

There are occasional reports on the nanoVNA list (https://groups.io/g/nanovna-users) of touch screens failing due to cases fouling the surface. The usual solution seems to be to add washers or shims. One also has a vague recollection of solder splashes being a problem.

HTH, 73, Stay Safe,

Robin, G8DQX

On 21/03/2021 13:04, Andy G4JNT wrote:
Update.
I removed front ang back covers, and it started to - sort of - work.  The touch screen is a total failure, but I can drive it using the manual button thing.  replaced the covers and it stayed working.    SO I'm guessing an intermittent in a ribbon cable link on the touchscreen.
SO it has been saved from the sledgehammer for now.

Also took the opportunity to look inside, including lifting the covers over the RF portion. Pretty boring; three NE602 mixer chips, something that is obviously a soundcard type interface chip and one that is probably an Si family synth  - although the number was a bit meaningless.



Re: Original NanoVNA a waste of money

Nick
 

Andy

I also have an original 2.8" nanovna repackaged in a diecast box with N-type connectors and a bigger battery.

Suggest you charge the battery, install latest firmware and give yours a careful touch calibration before trashing it.

Be sure to use the correct firmware i.e. the -H version not the -H4.

https://github.com/hugen79/NanoVNA-H/releases
https://groups.io/g/nanovna-users/topics

HTH

Nick

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