Stretching the topic slightly for ADF4351 boards


G8ACE
 

All Synthesists,
I noted this morning AliExpress is selling a programmable ADF synth board with LCD readout for under 10 GBP.  Needless to say this bargain is not deliverable to UK.
So as ever one checks the other sauce,  Banggood.  They have it there VAT paid.  £19.26  inc. shipping at todays exchange rate.  The pcb is different again to those we have become used to using however as you get a complete generator for not a lot more than the last black board I purchased I thought it worth a punt especially as I am get lazy to build these things.  Just ordered one from Banggood so unable to give a revue at this time but thouight it worth passing on the find for others also feeling build lazy.
AliExpress also do the same unit different supplier costing more than Banggood.
I am not seeing an explanation for the use of the USB socket.  On board ref frequency I have not seen either.  Stability might be suspect using the on board ref but could be a useful toy for ones experiments box.



If you check AliExpress as well as Banggood more pictures are shown with the board in more detail.
I have not had any difficulties buying from Banggood.  Its always worth comparing Bangood with AliExpress for price and sometimes items are ready to be shipped from UK but not this time.  Both suppliers can be cheaper than ePay at times.

73s John G8ACE


Colin Ranson
 

Hi John

I got one of these from China a couple of years go, tested it to make sure it worked then relegated it to the drawer.

Only last week fired it up again – 1KHz high at 2m, a couple high at 70cm, several at 3400MHz, a some inband birdies at low level, not able to measure phase noise etc.

A useful tool.    Wondering if a stable and accurate 25MHz injection would improve accuracy ?   Theres also another XTAL on the lower board, don’t know its value or its function

 

Regards      Colin de G8LBS.

 

Sent from Mail for Windows

 

From: G8ACE
Sent: 06 September 2021 11:18
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Stretching the topic slightly for ADF4351 boards

 

All Synthesists,
I noted this morning AliExpress is selling a programmable ADF synth board with LCD readout for under 10 GBP.  Needless to say this bargain is not deliverable to UK.
So as ever one checks the other sauce,  Banggood.  They have it there VAT paid.  £19.26  inc. shipping at todays exchange rate.  The pcb is different again to those we have become used to using however as you get a complete generator for not a lot more than the last black board I purchased I thought it worth a punt especially as I am get lazy to build these things.  Just ordered one from Banggood so unable to give a revue at this time but thouight it worth passing on the find for others also feeling build lazy.
AliExpress also do the same unit different supplier costing more than Banggood.
I am not seeing an explanation for the use of the USB socket.  On board ref frequency I have not seen either.  Stability might be suspect using the on board ref but could be a useful toy for ones experiments box.



If you check AliExpress as well as Banggood more pictures are shown with the board in more detail.
I have not had any difficulties buying from Banggood.  Its always worth comparing Bangood with AliExpress for price and sometimes items are ready to be shipped from UK but not this time.  Both suppliers can be cheaper than ePay at times.

73s John G8ACE

 


geoffrey pike
 

Is the minimum step 1 KHz or 10 KHz?
Geoff
GI0GDP

On Monday, 6 September 2021, 12:08:41 BST, Colin Ranson <g8lbs@...> wrote:


Hi John

I got one of these from China a couple of years go, tested it to make sure it worked then relegated it to the drawer.

Only last week fired it up again – 1KHz high at 2m, a couple high at 70cm, several at 3400MHz, a some inband birdies at low level, not able to measure phase noise etc.

A useful tool.    Wondering if a stable and accurate 25MHz injection would improve accuracy ?   Theres also another XTAL on the lower board, don’t know its value or its function

 

Regards      Colin de G8LBS.

 

Sent from Mail for Windows

 

From: G8ACE
Sent: 06 September 2021 11:18
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Stretching the topic slightly for ADF4351 boards

 

All Synthesists,
I noted this morning AliExpress is selling a programmable ADF synth board with LCD readout for under 10 GBP.  Needless to say this bargain is not deliverable to UK.
So as ever one checks the other sauce,  Banggood.  They have it there VAT paid.  £19.26  inc. shipping at todays exchange rate.  The pcb is different again to those we have become used to using however as you get a complete generator for not a lot more than the last black board I purchased I thought it worth a punt especially as I am get lazy to build these things.  Just ordered one from Banggood so unable to give a revue at this time but thouight it worth passing on the find for others also feeling build lazy.
AliExpress also do the same unit different supplier costing more than Banggood.
I am not seeing an explanation for the use of the USB socket.  On board ref frequency I have not seen either.  Stability might be suspect using the on board ref but could be a useful toy for ones experiments box.



If you check AliExpress as well as Banggood more pictures are shown with the board in more detail.
I have not had any difficulties buying from Banggood.  Its always worth comparing Bangood with AliExpress for price and sometimes items are ready to be shipped from UK but not this time.  Both suppliers can be cheaper than ePay at times.

73s John G8ACE

 


Colin Ranson
 

Geoff,  its 1KHz... them 10...then 100...then 1MHz. The < > button scrolls through them all.

 

On switch on, if you want 2556mhz press 2556 then zero until display reads 2556.000 MHz then press ok to output.  Use < > to select step then + + and - - to tweak onto (or almost !) frequency.  C is cancel all.

 

 

At some point I will try to injection lock with 25MHz from my Chinese ‘gold’ oscillator

which is only a little out but when multiplied by 390 in an LNB put QO100 about 3.9KHz out !

 

 

 

Regards

 

 

Colin de G8LBS.

 

Sent from Mail for Windows

 

From: geoffrey pike via groups.io
Sent: 06 September 2021 13:14
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Stretching the topic slightly for ADF4351 boards

 

Is the minimum step 1 KHz or 10 KHz?

Geoff

GI0GDP

 

On Monday, 6 September 2021, 12:08:41 BST, Colin Ranson <g8lbs@...> wrote:

 

 

Hi John

I got one of these from China a couple of years go, tested it to make sure it worked then relegated it to the drawer.

Only last week fired it up again – 1KHz high at 2m, a couple high at 70cm, several at 3400MHz, a some inband birdies at low level, not able to measure phase noise etc.

A useful tool.    Wondering if a stable and accurate 25MHz injection would improve accuracy ?   Theres also another XTAL on the lower board, don’t know its value or its function

 

Regards      Colin de G8LBS.

 

Sent from Mail for Windows

 

From: G8ACE
Sent: 06 September 2021 11:18
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Stretching the topic slightly for ADF4351 boards

 

All Synthesists,
I noted this morning AliExpress is selling a programmable ADF synth board with LCD readout for under 10 GBP.  Needless to say this bargain is not deliverable to UK.
So as ever one checks the other sauce,  Banggood.  They have it there VAT paid.  £19.26  inc. shipping at todays exchange rate.  The pcb is different again to those we have become used to using however as you get a complete generator for not a lot more than the last black board I purchased I thought it worth a punt especially as I am get lazy to build these things.  Just ordered one from Banggood so unable to give a revue at this time but thouight it worth passing on the find for others also feeling build lazy.
AliExpress also do the same unit different supplier costing more than Banggood.
I am not seeing an explanation for the use of the USB socket.  On board ref frequency I have not seen either.  Stability might be suspect using the on board ref but could be a useful toy for ones experiments box.



If you check AliExpress as well as Banggood more pictures are shown with the board in more detail.
I have not had any difficulties buying from Banggood.  Its always worth comparing Bangood with AliExpress for price and sometimes items are ready to be shipped from UK but not this time.  Both suppliers can be cheaper than ePay at times.

73s John G8ACE

 

 


Stefan
 

Hi John and all

I bought some a year ago and have not made much use of it. The XTAL is quite a bit of frequency If i recall 50khz out on the microwave freq unfortunately there is no provision to change the ref freq to 10Mhz on the unit unless someone is clever enough to connect to the ICSP header and modify the scrip. The USB connector is for 5V only. Spurs and phase noise is as expected avg.
As a portable source or a simple sig gen they are great!

Stefan VK4CSD 73


----- Original Message -----
From:
UKMicrowaves@groups.io

To:
<UKMicrowaves@groups.io>
Cc:

Sent:
Mon, 06 Sep 2021 03:18:36 -0700
Subject:
Re: [UKMicrowaves] Stretching the topic slightly for ADF4351 boards


All Synthesists,
I noted this morning AliExpress is selling a programmable ADF synth board with LCD readout for under 10 GBP.  Needless to say this bargain is not deliverable to UK.
So as ever one checks the other sauce,  Banggood.  They have it there VAT paid.  £19.26  inc. shipping at todays exchange rate.  The pcb is different again to those we have become used to using however as you get a complete generator for not a lot more than the last black board I purchased I thought it worth a punt especially as I am get lazy to build these things.  Just ordered one from Banggood so unable to give a revue at this time but thouight it worth passing on the find for others also feeling build lazy.
AliExpress also do the same unit different supplier costing more than Banggood.
I am not seeing an explanation for the use of the USB socket.  On board ref frequency I have not seen either.  Stability might be suspect using the on board ref but could be a useful toy for ones experiments box.



If you check AliExpress as well as Banggood more pictures are shown with the board in more detail.
I have not had any difficulties buying from Banggood.  Its always worth comparing Bangood with AliExpress for price and sometimes items are ready to be shipped from UK but not this time.  Both suppliers can be cheaper than ePay at times.

73s John G8ACE

Email sent using Optus Webmail


iw5bsf f Roberto
 

Hi I also bought the sitentizator on ebay but then stored in a small box I was disappointed, after some time I discovered the quite simple PA0RWE project I was satisfied l it works really well !!!!!
link
https://pa0rwe.nl/?page_id=65

73 de iw5bsf Roberto


G8ACE
 

Thanks to all for the additional info on the ADF board with PIC and LCD that I had not seen previously.

A couple of points.  Its quite likely that the stability of the on pcb 25 MHz ref can be improved by insulating the crystal with some polystyrene.
In effect using the pcb as an oven for the crystal.  The actual frequency accuracy may not be improved but improved stability is worthwhile.

I see in the circuit provided by Roberto, thanks, that a 10 MHz clock crystal is shown for the PIC.  If  another 10 MHz crystal is also used for the ADF ref input its pretty certain that these two crystals will talk to each other even when physically a few centimetres apart.  The difference frequency may well produce unwanted spurs.  This was a trap the 122 GHz project fell into when a 10 MHz external ref was added for extra 122 GHz stability.  Using the ADF ref also as an external PIC clock should cure any problem.

73s John G8ACE


Andy G4JNT
 

The same problem reared its head when the RDDS locking system was developed.   A 10MHz PIC clock interfered with the 10MHz reference and it's sensitive locking circuitry.   The solution was to change the PIC clock to 11.2896MHz



On Tue, 7 Sept 2021 at 09:22, G8ACE <hazellje@...> wrote:
Thanks to all for the additional info on the ADF board with PIC and LCD that I had not seen previously.

A couple of points.  Its quite likely that the stability of the on pcb 25 MHz ref can be improved by insulating the crystal with some polystyrene.
In effect using the pcb as an oven for the crystal.  The actual frequency accuracy may not be improved but improved stability is worthwhile.

I see in the circuit provided by Roberto, thanks, that a 10 MHz clock crystal is shown for the PIC.  If  another 10 MHz crystal is also used for the ADF ref input its pretty certain that these two crystals will talk to each other even when physically a few centimetres apart.  The difference frequency may well produce unwanted spurs.  This was a trap the 122 GHz project fell into when a 10 MHz external ref was added for extra 122 GHz stability.  Using the ADF ref also as an external PIC clock should cure any problem.

73s John G8ACE


Colin Ranson
 

Hi John -  as you said  “Its quite likely that the stability of the on pcb 25 MHz ref can be improved by insulating the crystal with some polystyrene.”   Mine is in a cardboard box and has been running for two days now on 3400.200MHz, its about 55KHz low and just about stays within the SSB passband of my IC-706MK2g and SG Labs transverter unless subjected to a draft ! – like blowing into the box – then its gone !

 

A die cast box with insulation and plastic push rods (through a thick ally guide plate) for the micro switches is called for.

 

It will only still be a useful play thing not to be incorporated into anything.

 

Regards,    Colin de G8LBS.

 

PS, still looking to buy for a multipole 3.4GHz interdigital filter. Anybody ?

 



 

Sent from Mail for Windows

 

From: Andy G4JNT
Sent: 07 September 2021 09:49
To: UK Microwaves groups.io
Subject: Re: [UKMicrowaves] Stretching the topic slightly for ADF4351 boards

 

The same problem reared its head when the RDDS locking system was developed.   A 10MHz PIC clock interfered with the 10MHz reference and it's sensitive locking circuitry.   The solution was to change the PIC clock to 11.2896MHz

 

Andy

 

 

 

On Tue, 7 Sept 2021 at 09:22, G8ACE <hazellje@...> wrote:

Thanks to all for the additional info on the ADF board with PIC and LCD that I had not seen previously.

A couple of points.  Its quite likely that the stability of the on pcb 25 MHz ref can be improved by insulating the crystal with some polystyrene.
In effect using the pcb as an oven for the crystal.  The actual frequency accuracy may not be improved but improved stability is worthwhile.

I see in the circuit provided by Roberto, thanks, that a 10 MHz clock crystal is shown for the PIC.  If  another 10 MHz crystal is also used for the ADF ref input its pretty certain that these two crystals will talk to each other even when physically a few centimetres apart.  The difference frequency may well produce unwanted spurs.  This was a trap the 122 GHz project fell into when a 10 MHz external ref was added for extra 122 GHz stability.  Using the ADF ref also as an external PIC clock should cure any problem.

73s John G8ACE

 


iw5bsf f Roberto
 
Edited

unfortunately the quality of the Chinese 25 mhz oscillators is poor. I solved the spurs problem by soldering small pieces of 0.1mm copper my surprise are almost completely gone as well as adding two 1000 uf capacitors on the 3.3v stabilizer, reducing phase noise in addition added low pass filter on the reference the results are in the photograph
the noise level before the change I spent several hours bye bye
ps for the less lazy I designed the pcb board if anyone was interested mertto the pcb file designed by  all l of the generator pa0rwe 73 de iw5bsf Roberto


Colin Ranson
 

Hi Roberto,

 

The pic showing the placement of the small bits of copper is blurred, can you provide a sharper picture please ?

 

Thank you

 

Regards

 

Colin de G8LBS.

 

Sent from Mail for Windows

 

From: Roberto
Sent: 07 September 2021 17:42
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Stretching the topic slightly for ADF4351 boards

 

[Edited Message Follows]

unfortunately the quality of the Chinese 25 mhz oscillators is poor. I solved the spurs problem by soldering small pieces of 0.1mm copper my surprise are almost completely gone as well as adding two 1000 uf capacitors on the 3.3v stabilizer, reducing phase noise in addition added low pass filter on the reference the results are in the photograph
the noise level before the change I spent several hours bye bye
ps for the less lazy I designed the pcb board if anyone was interested mertto the pcb file designed by  all l of the generator pa0rwe 73 de iw5bsf Roberto

 


iw5bsf f Roberto
 

Hello  Colin I put the image back I hope it is clearer

update
Today I modified another pll board adf4351 with 124.500 MHz dual frequency oscillator for transverter to be injected instead of 24 GHz quartz and trv 24 ghz 2.988 GHz x4 here are the photos pdate
73 Roberto


G8ACE
 

On Mon, Sep 6, 2021 at 09:26 PM, Stefan wrote:
All Synthesists,  an update.
My ADF4351 module with LCD and input buttons arrived from Banggood.
A quick look at frequency accuracy.  3.5Hz low at 4.4GHz at ambient 20C (GPS 10 MHz counter ref)
Unfortunately warming the crystal with a finger sent the frequency further LF and so a simple oven with a resistor across the 25 Meg crystal isnt going to work.
In my view that accuracy isnt bad for a cheap jack come handy source.

Its interesting that the price of this unit with PIC ? buttons and display is much the same as the ADF black pcb with less on it.  Clearly to much demand for the black pcb has pushed the price up.
Its even worse for the ADF4355

73s John G8ACE