Date   

Re: Tropo across the North Sea

John Fell
 

Hi Marcus ,
Your reference to the N Yorks Moors rang a bell with me as I was at Danby Beacon , above Eskdale, about 5 years ago at almost the same day as Neil's DX .Using a 20dBi PCB horn and a locked Octagon LNB , I heard several 10GHz Dutch and German beacons at good strength .Best DX was a germany beacon near to DEnmark , would have been in East Germany at one time .Very obvious mist and ducting no doubt over the North sea at that ASL in IO94 .
I only went up to see if I could hear the then quite new GB3FNY - which I did circa 549 .

Away in S Devon at mo so no RF ...

73
John
G0API

On Tue, 7 Sept 2021 at 16:54, Neil Smith G4DBN <neil@...> wrote:

It's a pity I didn't have antenna for other bands up at the time so I could characterise the path at multiple frequencies from VHF upwards. I must try harder...

Thanks for the analysis Marcus. 50% aperture efficiency might be a little generous, as the feedhorn I am using provides and edge taper around 9 dB, so there is a bit of over-illumination. I usually say 36 dBi as the likely gain.  The Kuhne w/g preamp claims about 0.7 dB, and I have at least 0.5dB of loss in the w/g relay and guide. The sun vs cold sky noise gives a result that would match 36 dBi and 1.5 dB system NF, at least by my manual calculations and the VK3UM spreadsheet.

The over-illumination is not too important for terrestrial as the overspill points mainly cold cold sky. My new setup will have a sharper and cleaner pattern, with about a 12 dB average edge taper after taking space attenuation into account at the offset dish edges, plus the w/g relay and preamp will be right on the back of the feed

I collimate the setup using sun noise as there are no beacons available from here via a clean path. I'm surrounded by forests of wind turbines.

The measured SNR from DB0XY in 11.7 Hz SDR bins peaked over 23 dB for 15 minutes or so.  I wasn't able to see any reflection from the top of the 850 ft chimney at Drax, so I don't think it was in the duct. Perhaps I was getting into it somewhere over North East Lincs.  On several occasions previously, I've found very strong signals from EU beacons reflected off Drax when the direct path was weak or non-existent.

I should ask if I can fit steerable passive reflector up there, but there are 1,460 steps up the ladder, or a clunky rack and pinion lift similar to the one at Emley Moor. I've been up that one.  Once. That was enough. <shudder>

Neil G4DBN

On 07/09/2021 15:03, Marcus Walden wrote:
Some back-of-the-envelope calculations:

DB0XY ERP is 15 W (+41.8 dBm). So the EIRP is close to +44 dBm.

Your dish has a directivity of about 40 dBi at 10 GHz, so gain might be about 37 dBi assuming 50% aperture efficiency (you'll know actual gain better than me).

Assuming 1 dB noise figure, 500 Hz bandwidth and 10 dB SNR, the minimum sensitivity is about -136 dBm.

That suggests a maximum allowable path loss of about 44 + 37 + 136 = 217 dB, which is close to the predicted path loss using the Norderney radiosonde data for 0000 UTC on 4 September 2021.

73 Marcus G0IJZ

On Tue, 7 Sept 2021 at 11:02, Neil Smith G4DBN <neil@...> wrote:

I have a 0.95 m offset dish at 13 metres, using a Pickett-Potter feedhorn with waveguide relay and waveguide-input preamp. The path to DB0XY is pretty much straight down the Humber estuary, with one small ridge about 80m high to the south of the Humber Bridge.

Neil G4DBN

On 07/09/2021 09:23, Marcus Walden wrote:
Hi Neil

I looked at radiosonde data for Norderney (Northern Germany) for Friday and Saturday and there was a very strong elevated duct, which varied in height. Analysis of the duct parameters suggest it was strong enough to support low VHF, which is confirmed by your observations for the weekend.

1200 UTC 3 Sept 2021 Duct top at ~750 m and depth ~350 m  
0000 UTC 4 Sept 2021 Duct top at ~850 m and depth ~300 m  
1200 UTC 4 Sept 2021 Duct top at ~1220 m and depth ~270 m

The duct over Norderney was rising over time. Midday Friday, the beacon altitude was close to or just above the top of the duct at Norderney. At midnight, it was within the duct and midday Saturday it was below the duct.

On the assumption that the Norderney conditions at 0000 UTC extended from DB0XY to you (not likely because the duct will vary with height and distance), the attached path loss prediction might be of interest. Flat Earth shown. Had you been on peaks in the North York Moors or the Yorkshire Dales, reception of the beacon would have been even stronger.
image.png

I think you had a Goldilocks moment, where conditions were just right for you. There appears to have been just enough leakage from the duct to your station to overcome the large amount of path loss at 10 GHz.

Out of curiosity, what is your 10 GHz antenna?

By the way, the Hawaii-California tropospheric ducting links are similar. When the Hawaii beacons are sitting in the duct (~2500 m altitude) and the duct extends and slopes down towards coastal California, then the links work. 

73 Marcus G0IJZ



-- 
Neil
http://g4dbn.uk


Re: Stretching the topic slightly for ADF4351 boards

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


Re: Tropo across the North Sea

Neil Smith G4DBN
 

It's a pity I didn't have antenna for other bands up at the time so I could characterise the path at multiple frequencies from VHF upwards. I must try harder...

Thanks for the analysis Marcus. 50% aperture efficiency might be a little generous, as the feedhorn I am using provides and edge taper around 9 dB, so there is a bit of over-illumination. I usually say 36 dBi as the likely gain.  The Kuhne w/g preamp claims about 0.7 dB, and I have at least 0.5dB of loss in the w/g relay and guide. The sun vs cold sky noise gives a result that would match 36 dBi and 1.5 dB system NF, at least by my manual calculations and the VK3UM spreadsheet.

The over-illumination is not too important for terrestrial as the overspill points mainly cold cold sky. My new setup will have a sharper and cleaner pattern, with about a 12 dB average edge taper after taking space attenuation into account at the offset dish edges, plus the w/g relay and preamp will be right on the back of the feed

I collimate the setup using sun noise as there are no beacons available from here via a clean path. I'm surrounded by forests of wind turbines.

The measured SNR from DB0XY in 11.7 Hz SDR bins peaked over 23 dB for 15 minutes or so.  I wasn't able to see any reflection from the top of the 850 ft chimney at Drax, so I don't think it was in the duct. Perhaps I was getting into it somewhere over North East Lincs.  On several occasions previously, I've found very strong signals from EU beacons reflected off Drax when the direct path was weak or non-existent.

I should ask if I can fit steerable passive reflector up there, but there are 1,460 steps up the ladder, or a clunky rack and pinion lift similar to the one at Emley Moor. I've been up that one.  Once. That was enough. <shudder>

Neil G4DBN

On 07/09/2021 15:03, Marcus Walden wrote:
Some back-of-the-envelope calculations:

DB0XY ERP is 15 W (+41.8 dBm). So the EIRP is close to +44 dBm.

Your dish has a directivity of about 40 dBi at 10 GHz, so gain might be about 37 dBi assuming 50% aperture efficiency (you'll know actual gain better than me).

Assuming 1 dB noise figure, 500 Hz bandwidth and 10 dB SNR, the minimum sensitivity is about -136 dBm.

That suggests a maximum allowable path loss of about 44 + 37 + 136 = 217 dB, which is close to the predicted path loss using the Norderney radiosonde data for 0000 UTC on 4 September 2021.

73 Marcus G0IJZ

On Tue, 7 Sept 2021 at 11:02, Neil Smith G4DBN <neil@...> wrote:

I have a 0.95 m offset dish at 13 metres, using a Pickett-Potter feedhorn with waveguide relay and waveguide-input preamp. The path to DB0XY is pretty much straight down the Humber estuary, with one small ridge about 80m high to the south of the Humber Bridge.

Neil G4DBN

On 07/09/2021 09:23, Marcus Walden wrote:
Hi Neil

I looked at radiosonde data for Norderney (Northern Germany) for Friday and Saturday and there was a very strong elevated duct, which varied in height. Analysis of the duct parameters suggest it was strong enough to support low VHF, which is confirmed by your observations for the weekend.

1200 UTC 3 Sept 2021 Duct top at ~750 m and depth ~350 m  
0000 UTC 4 Sept 2021 Duct top at ~850 m and depth ~300 m  
1200 UTC 4 Sept 2021 Duct top at ~1220 m and depth ~270 m

The duct over Norderney was rising over time. Midday Friday, the beacon altitude was close to or just above the top of the duct at Norderney. At midnight, it was within the duct and midday Saturday it was below the duct.

On the assumption that the Norderney conditions at 0000 UTC extended from DB0XY to you (not likely because the duct will vary with height and distance), the attached path loss prediction might be of interest. Flat Earth shown. Had you been on peaks in the North York Moors or the Yorkshire Dales, reception of the beacon would have been even stronger.
image.png

I think you had a Goldilocks moment, where conditions were just right for you. There appears to have been just enough leakage from the duct to your station to overcome the large amount of path loss at 10 GHz.

Out of curiosity, what is your 10 GHz antenna?

By the way, the Hawaii-California tropospheric ducting links are similar. When the Hawaii beacons are sitting in the duct (~2500 m altitude) and the duct extends and slopes down towards coastal California, then the links work. 

73 Marcus G0IJZ



-- 
Neil
http://g4dbn.uk


Re: Tropo across the North Sea

Marcus Walden
 

Some back-of-the-envelope calculations:

DB0XY ERP is 15 W (+41.8 dBm). So the EIRP is close to +44 dBm.

Your dish has a directivity of about 40 dBi at 10 GHz, so gain might be about 37 dBi assuming 50% aperture efficiency (you'll know actual gain better than me).

Assuming 1 dB noise figure, 500 Hz bandwidth and 10 dB SNR, the minimum sensitivity is about -136 dBm.

That suggests a maximum allowable path loss of about 44 + 37 + 136 = 217 dB, which is close to the predicted path loss using the Norderney radiosonde data for 0000 UTC on 4 September 2021.

73 Marcus G0IJZ

On Tue, 7 Sept 2021 at 11:02, Neil Smith G4DBN <neil@...> wrote:

I have a 0.95 m offset dish at 13 metres, using a Pickett-Potter feedhorn with waveguide relay and waveguide-input preamp. The path to DB0XY is pretty much straight down the Humber estuary, with one small ridge about 80m high to the south of the Humber Bridge.

Neil G4DBN

On 07/09/2021 09:23, Marcus Walden wrote:
Hi Neil

I looked at radiosonde data for Norderney (Northern Germany) for Friday and Saturday and there was a very strong elevated duct, which varied in height. Analysis of the duct parameters suggest it was strong enough to support low VHF, which is confirmed by your observations for the weekend.

1200 UTC 3 Sept 2021 Duct top at ~750 m and depth ~350 m  
0000 UTC 4 Sept 2021 Duct top at ~850 m and depth ~300 m  
1200 UTC 4 Sept 2021 Duct top at ~1220 m and depth ~270 m

The duct over Norderney was rising over time. Midday Friday, the beacon altitude was close to or just above the top of the duct at Norderney. At midnight, it was within the duct and midday Saturday it was below the duct.

On the assumption that the Norderney conditions at 0000 UTC extended from DB0XY to you (not likely because the duct will vary with height and distance), the attached path loss prediction might be of interest. Flat Earth shown. Had you been on peaks in the North York Moors or the Yorkshire Dales, reception of the beacon would have been even stronger.
image.png

I think you had a Goldilocks moment, where conditions were just right for you. There appears to have been just enough leakage from the duct to your station to overcome the large amount of path loss at 10 GHz.

Out of curiosity, what is your 10 GHz antenna?

By the way, the Hawaii-California tropospheric ducting links are similar. When the Hawaii beacons are sitting in the duct (~2500 m altitude) and the duct extends and slopes down towards coastal California, then the links work. 

73 Marcus G0IJZ




Re: Stretching the topic slightly for ADF4351 boards

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

 


Re: Tropo across the North Sea

Neil Smith G4DBN
 

I have a 0.95 m offset dish at 13 metres, using a Pickett-Potter feedhorn with waveguide relay and waveguide-input preamp. The path to DB0XY is pretty much straight down the Humber estuary, with one small ridge about 80m high to the south of the Humber Bridge.

Neil G4DBN

On 07/09/2021 09:23, Marcus Walden wrote:
Hi Neil

I looked at radiosonde data for Norderney (Northern Germany) for Friday and Saturday and there was a very strong elevated duct, which varied in height. Analysis of the duct parameters suggest it was strong enough to support low VHF, which is confirmed by your observations for the weekend.

1200 UTC 3 Sept 2021 Duct top at ~750 m and depth ~350 m  
0000 UTC 4 Sept 2021 Duct top at ~850 m and depth ~300 m  
1200 UTC 4 Sept 2021 Duct top at ~1220 m and depth ~270 m

The duct over Norderney was rising over time. Midday Friday, the beacon altitude was close to or just above the top of the duct at Norderney. At midnight, it was within the duct and midday Saturday it was below the duct.

On the assumption that the Norderney conditions at 0000 UTC extended from DB0XY to you (not likely because the duct will vary with height and distance), the attached path loss prediction might be of interest. Flat Earth shown. Had you been on peaks in the North York Moors or the Yorkshire Dales, reception of the beacon would have been even stronger.
image.png

I think you had a Goldilocks moment, where conditions were just right for you. There appears to have been just enough leakage from the duct to your station to overcome the large amount of path loss at 10 GHz.

Out of curiosity, what is your 10 GHz antenna?

By the way, the Hawaii-California tropospheric ducting links are similar. When the Hawaii beacons are sitting in the duct (~2500 m altitude) and the duct extends and slopes down towards coastal California, then the links work. 

73 Marcus G0IJZ




Re: Stretching the topic slightly for ADF4351 boards

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


Re: Tropo across the North Sea

Marcus Walden
 

Hi Neil

I looked at radiosonde data for Norderney (Northern Germany) for Friday and Saturday and there was a very strong elevated duct, which varied in height. Analysis of the duct parameters suggest it was strong enough to support low VHF, which is confirmed by your observations for the weekend.

1200 UTC 3 Sept 2021 Duct top at ~750 m and depth ~350 m  
0000 UTC 4 Sept 2021 Duct top at ~850 m and depth ~300 m  
1200 UTC 4 Sept 2021 Duct top at ~1220 m and depth ~270 m

The duct over Norderney was rising over time. Midday Friday, the beacon altitude was close to or just above the top of the duct at Norderney. At midnight, it was within the duct and midday Saturday it was below the duct.

On the assumption that the Norderney conditions at 0000 UTC extended from DB0XY to you (not likely because the duct will vary with height and distance), the attached path loss prediction might be of interest. Flat Earth shown. Had you been on peaks in the North York Moors or the Yorkshire Dales, reception of the beacon would have been even stronger.
image.png

I think you had a Goldilocks moment, where conditions were just right for you. There appears to have been just enough leakage from the duct to your station to overcome the large amount of path loss at 10 GHz.

Out of curiosity, what is your 10 GHz antenna?

By the way, the Hawaii-California tropospheric ducting links are similar. When the Hawaii beacons are sitting in the duct (~2500 m altitude) and the duct extends and slopes down towards coastal California, then the links work. 

73 Marcus G0IJZ


On Sat, 4 Sept 2021 at 01:36, Gedas <w8bya@...> wrote:

What an excellent and exciting summary Neil. It is fascinating how the dynamics differ between NA and western Europe. 10 GHz is such an amazing band with so many propagation modes available. A little bit of something for everyone. TU es 73

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 9/3/2021 8:12 PM, Neil Smith G4DBN wrote:

Lots of action on 23cm and VHF, and lot of 10 GHz much further East, for instance from OK to DB0GHZ in JN34 and DB0VC in JO54.  On 23cm Italy to Germany and GI/GM to PA and some action on 13cm. The F5LEN tropo maps looked very promising indeed for the last few days over most of the southern North Sea, extending as far as the coast of Poland in the Baltic, but I am 64 km from the nearest sea coast, with 500ft hills in the path to SM/OZ and 85 km on the path to PA, and 230km to Belgium/France, so a long way before I hit the ducting over the North Sea. The usual beacons at 250-350 km range were totally absent, and I couldn't hear ANY EU beacons at all for the last two days when the tropo maps looked to great, so I guess any duct was way over my head (I am 12ft above sea level) or never reached me over the coastal hills. The path to PI7ALK, DB0WML, DB0MU and DB0XY goes through a gap in the hills, but I have not heard anything from the the first three, which are 400-500 km away, just DB0XY at nearly 800 km, but it is on a good-sized hill.  The only UK beacon I could hear other than the two fairly local ones was GB3OSW, which is only 100 miles away, but over several 1800 ft hills.

Another feature of the DB0XY path was that I heard it at least four degrees south of the direct path.  These skewed paths often appear when I'm at the edge of a patch of tropo ducting. Sometimes the skew is 60 to 90 degrees, but more often just 5-10 degrees.

Neil G4DBN

On 03/09/2021 23:42, Gedas wrote:

Neal, very cool ! Can you tell me if there were any enhancements over this path on lower freq's like 2m etc? Map aids like APRS etc.

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 9/3/2021 6:25 PM, Neil Smith G4DBN wrote:
So far, the tropo has been a huge disappointment on 10 GHz, but I just heard a nice signal from DB0XY on JO51 at 787 km. it was fully Q5 for 10 minutes or so, then faded again. The beacon is at 700 metres so perhaps the duct is only accessible from height at 10 GHz? DB0XY is behind a 180 m hill from here. It is on almost the same heading as some closer beacons which I haven't heard at all (PI7ALK, DB0WML, DB0MU etc).

I was beginning to think I had a receiver fault as CAM is weak and there is nil from the usually-reliable KBQ and PKT.

_._


Re: Stretching the topic slightly for ADF4351 boards

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


Re: Stretching the topic slightly for ADF4351 boards

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


Re: Stretching the topic slightly for ADF4351 boards

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


Re: Stretching the topic slightly for ADF4351 boards

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

 

 


Re: Searching for sampling mixer

Maarten PA0MHE
 

On the input of the mixer the 8001MHz is around -3dBm, the LO is 13dBm. The wanted output on 1MHz below -110dBm is present at all. So far below the expected -60 .. 65dBm
Still I don't understand why such a mixer fails; as there is no possibility to overload him.


Re: Stretching the topic slightly for ADF4351 boards

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

 


Re: Stretching the topic slightly for ADF4351 boards

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

 


Re: Searching for sampling mixer

Andy G4JNT
 

As a rule of thumb, for harmonic conversion loss use 20.LOG(N) above the normal mixer loss
SO for 240 times 20.LOG(240) = 48dB
Allow say 10dB additional loss so you may be looking at nearly 60dB



On Mon, 6 Sept 2021 at 10:33, Maarten PA0MHE <maarten.heuvelman@...> wrote:
Hi John,
I will try.... to measure the diodes, though it is all verrrry small. Need to do it under a microscope.
2 Questions:
- what order of conversion loss should I expect from the 240x harmonic ? any idea ? 8001 - (240 x 33.33) = 1 MHz
- Do you or someone has a principle diagram of such a mixer, as I see more components ? Is such mixer very different from a "normal" harmonic mixer used in a SA, were frequency ranges are very different. ?

73's Maarten


Re: 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


Re: Searching for sampling mixer

Maarten PA0MHE
 

Hi John,
I will try.... to measure the diodes, though it is all verrrry small. Need to do it under a microscope.
2 Questions:
- what order of conversion loss should I expect from the 240x harmonic ? any idea ? 8001 - (240 x 33.33) = 1 MHz
- Do you or someone has a principle diagram of such a mixer, as I see more components ? Is such mixer very different from a "normal" harmonic mixer used in a SA, were frequency ranges are very different. ?

73's Maarten


Re: Searching for sampling mixer

John E. Beech
 

Hi Maarten,
It looks similar to mine, but it is a long time since I did the repair. Your photo seems to show an X-
package in the centre. It might be worth putting a multimeter in diode test function round the leads to see if any of
them are open/short circuit. You should expect a Vf of about 0.3 v if they are Schottky types.

de John G8SEQ

-------Original Message-------
From: Maarten PA0MHE <maarten.heuvelman@gmail.com>
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Searching for sampling mixer
Sent: Sep 06 '21 09:00

Hi John,

It is a kind of Thin film circuit, see attached photo, do you
recognize it ?
When similar; such a HP device in an X-package would be also of great
help.

73's Maarten
2.12.0.0


Re: Searching for sampling mixer

Maarten PA0MHE
 

Hi John,
 
It is a kind of Thin film circuit, see attached photo, do you recognize it ?
When similar; such a HP device in an X-package would be also of great help.
 
 
73's Maarten

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