Short Wave Receiver - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

dave walsh · 10th Sep 2006, 9:08 pm

Paul-further to your pm earlier with the 1961 date there IS more info re the G3LOK. It is in the Bulletin December 1959. A Home Built Communications Receiver" by E St B Sydenham. There are 5 pages/circuit/text/photos/diagrams. It won a prize at the 1958 RSGB exhiibition. Home made coils/EF80/6AB6 etc no really impossible valves within the twelve I don't think. 6 bands from 1.8 megs but the last two are 20-27 and 27-40megs! You will need 2 x 2.1 IF cans. More difficult
than the 2 x 85k/cs ones perhaps. Dave

YC-156 · 10th Sep 2006, 9:24 pm

Dave,

Would you be able to post some additional technical details, please? Or the circuit perhaps?

I am particularly interested in valve lineup, which IFs it usess (2.1MHz?), how many stages of IF filtering, RF tages and crystal filters used, if any.

Well, that is actually a fair bit I'm asking for.

The circuit will do nicely if you have the possibility.

Frank N.

Skywave · 10th Sep 2006, 9:37 pm

I'lll echo that! Sounds interesting

I'm also particularly interested in the de-mod. ccts. I'll take AM and SSB as a given - but FM?

Al / G8DLH

dave walsh · 10th Sep 2006, 9:52 pm

Hi Frank-one Rf 2 x 2.1 IF stages 2 x 85k IF Stages Pentode mixer [sep osc] xtal control on 2nd IF/ d diode triode detector-Pentode output.
No extra filtering [I think]. Bandwith 2.5 k/cs at 6db.
EF80 6AK5 6BA6 ECH42 6BA6 6AT6 EB91 6AM5 6AM6 6AK5 VR150/30 5Z4G
I've not got the skills to put things up on the web but perhaps there is a way round that or there is always photocopying. Hope this helps. Dave

Sorry Al didn't understand the de mod/FM bit. Is it me? Dave
Sharing this machine so I'll check in later-please form a queue! Dave.

wireless_paul · 10th Sep 2006, 11:21 pm

Quote:

Originally Posted by dave walsh

Paul-further to your pm earlier with the 1961 date there IS more info re the G3LOK. It is in the Bulletin December 1959.

Hi Dave.
Thanks for looking this up for me. Could you possibly photo copy this article for me? Obviously I will pay any expenses.
Kind regards and thanks.
Paul

Skywave · 10th Sep 2006, 11:23 pm

Quote:

Originally Posted by dave walsh

Sorry Al didn't understand the de mod/FM bit. Is it me? Dave
Sharing this machine so I'll check in later-please form a queue! Dave.

OK. Sorry to be so brief / techy!

"de-mod" = demodulation. I assume that this RX will handle AM (!) and has a BFO. But does it use a product detector? And considering that the signal freq. goes as high as it does, it might contain a detector for FM / NBFM (narrow-band FM): not unusual for a RX to the low VHF band.

Al.

wireless_paul · 10th Sep 2006, 11:24 pm

Quote:

Originally Posted by Brian R Pateman

I can send the list to anyone else who wants it if you PM me

Hi Brian.
Have sent you a PM
Regards
Paul

dave walsh · 10th Sep 2006, 11:39 pm

Al I don't think it's a product detector or fm [1959 am radio?]. The extended hf bands are apparently to facilitate add on convertors for 2 and 4 metre working. Cost £10 to build but mainly from the junk box. Dave

dave walsh · 10th Sep 2006, 11:40 pm

Thats 1959 amateur radio sorry!

dave walsh · 11th Sep 2006, 11:40 am

Hi Paul I'll do you a photocopy asap. Have you got the facility to put it on line for people like Frank in Denmark? Dave

wireless_paul · 11th Sep 2006, 11:53 am

Hi Dave.
Yes I should (if I can work the scanner OK?) be able to send a copy to anyone who wants it. Not sure if you have my address. Will send you a PM.
Regards and thanks.
Paul

Station X · 11th Sep 2006, 12:32 pm

I have a pdf version of the whole of the December 1959 RSGB Bulletin. Trouble is it's a big file. About 11 Meg or 8 Meg zipped.

I'm happy to try emailing it to anyone who PMs me with their email address.

Perhaps someone has the software to extract the relevant pages and make a smaller file? I only have a pdf reader.

Mike Phelan · 11th Sep 2006, 1:42 pm

Graham
Just going to PM you for my email address. File size is no problem here. Depending on the layout, I may be able to split it up into graphics and OCR the text - we'll see.

Incidentally, none of the G2DAF stuff links work for me, even with broadband. Pity, as I remember it in the distant past and would like to have seen the articles, just for curiosity.

Mike Phelan · 11th Sep 2006, 3:25 pm

Graham has sent me the PDF and I have squashed the relevant article into a 369kb Word document. Here is the zip.

dave walsh · 11th Sep 2006, 4:24 pm

That's helpfull Mike and good quality but only 1/5 pages at my end. If you can get them all up could you send to Frank [Denmark] I wonder and save W Paul the job. Will you still need a photo copy with all these helpfull advanced technology people on stream Paul ? Dave.

radioman · 11th Sep 2006, 4:32 pm

All six pages loaded fine here.
Thanks Mike and Graham.

Andy

dave walsh · 11th Sep 2006, 4:38 pm

It's obviously a problem at my end, now got 2 pages after a bit of a wait. Perhaps I need more coal in the boiler? Of course I've got the mag anyway
but can someone make Frank's day please? Cheers Dave

YC-156 · 11th Sep 2006, 7:41 pm

Got it.

OpenOffice running on FreeBSD can read the doc file in this end.

I will give the article a closer look tomorrow.

Frank N.

YC-156 · 12th Sep 2006, 8:22 am

Have given the article a quick look, and I'm afraid this circuit is out of the running, since it isn't a general coverage receiver at all. If you look at the list of bands on page 1, it will be apparent - as the text also states - that this is a ham band receiver with a pair of excessively wide ranges, the higest ones.

Secondly the detector is obviously AM only, so no CW or SSB can be received as the receiver stands.

Finally I have a list of technical objections. This receiver - like most - is a compromise in many ways. I believe that even for a switched band receiver a much better performer could be built with the same number of valves. Particularly if we are allowed to sprinkle the design with a few more exotic components, like a high frequency crystal filter.

But I'm afraid my original comment still stands, so there is probably little reason in listing my objections. There is - to my knowledge - no cookie cutter DIY general coverage receiver designs using valves out there, assuming it should have reasonable performance.

Frank N.

Mike Phelan · 12th Sep 2006, 8:49 am

Quote:

Originally Posted by YC-156

Secondly the detector is obviously AM only, so no CW or SSB can be received as the receiver stands.

I did spot a BFO (V9) , Frank, so OK for SSB and CW.

Graham has sent me the G2DAF files, so I will put these up here in the next day or two.

10th Sep 2006, 9:08 pm	#21
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Re: Short Wave Receiver Paul-further to your pm earlier with the 1961 date there IS more info re the G3LOK. It is in the Bulletin December 1959. A Home Built Communications Receiver" by E St B Sydenham. There are 5 pages/circuit/text/photos/diagrams. It won a prize at the 1958 RSGB exhiibition. Home made coils/EF80/6AB6 etc no really impossible valves within the twelve I don't think. 6 bands from 1.8 megs but the last two are 20-27 and 27-40megs! You will need 2 x 2.1 IF cans. More difficult than the 2 x 85k/cs ones perhaps. Dave

10th Sep 2006, 9:24 pm	#22
YC-156 Retired Dormant Member Join Date: May 2005 Location: Aarhus, Denmark Posts: 281	Re: Short Wave Receiver Dave, Would you be able to post some additional technical details, please? Or the circuit perhaps? I am particularly interested in valve lineup, which IFs it usess (2.1MHz?), how many stages of IF filtering, RF tages and crystal filters used, if any. Well, that is actually a fair bit I'm asking for. The circuit will do nicely if you have the possibility. Frank N.

10th Sep 2006, 9:37 pm	#23
Skywave Rest in Peace Join Date: Jun 2006 Location: Chard, South Somerset, UK. Posts: 7,457	Re: Short Wave Receiver I'lll echo that! Sounds interesting I'm also particularly interested in the de-mod. ccts. I'll take AM and SSB as a given - but FM? Al / G8DLH

10th Sep 2006, 9:52 pm	#24
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Re: Short Wave Receiver Hi Frank-one Rf 2 x 2.1 IF stages 2 x 85k IF Stages Pentode mixer [sep osc] xtal control on 2nd IF/ d diode triode detector-Pentode output. No extra filtering [I think]. Bandwith 2.5 k/cs at 6db. EF80 6AK5 6BA6 ECH42 6BA6 6AT6 EB91 6AM5 6AM6 6AK5 VR150/30 5Z4G I've not got the skills to put things up on the web but perhaps there is a way round that or there is always photocopying. Hope this helps. Dave Sorry Al didn't understand the de mod/FM bit. Is it me? Dave Sharing this machine so I'll check in later-please form a queue! Dave.

10th Sep 2006, 11:39 pm	#28
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Re: Short Wave Receiver Al I don't think it's a product detector or fm [1959 am radio?]. The extended hf bands are apparently to facilitate add on convertors for 2 and 4 metre working. Cost £10 to build but mainly from the junk box. Dave

10th Sep 2006, 11:40 pm	#29
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Re: Short Wave Receiver Thats 1959 amateur radio sorry!

11th Sep 2006, 11:40 am	#30
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Re: Short Wave Receiver Hi Paul I'll do you a photocopy asap. Have you got the facility to put it on line for people like Frank in Denmark? Dave

11th Sep 2006, 11:53 am	#31
wireless_paul Hexode Join Date: Mar 2003 Location: World Heritage Village of Saltaire, Shipley, West Riding of Yorkshire. Posts: 324	Re: Short Wave Receiver Hi Dave. Yes I should (if I can work the scanner OK?) be able to send a copy to anyone who wants it. Not sure if you have my address. Will send you a PM. Regards and thanks. Paul

11th Sep 2006, 12:32 pm	#32
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Short Wave Receiver I have a pdf version of the whole of the December 1959 RSGB Bulletin. Trouble is it's a big file. About 11 Meg or 8 Meg zipped. I'm happy to try emailing it to anyone who PMs me with their email address. Perhaps someone has the software to extract the relevant pages and make a smaller file? I only have a pdf reader. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

11th Sep 2006, 1:42 pm	#33
Mike Phelan Dekatron Join Date: Nov 2003 Location: Near Leeds, West Yorkshire, UK Posts: 4,609	Re: Short Wave Receiver Graham Just going to PM you for my email address. File size is no problem here. Depending on the layout, I may be able to split it up into graphics and OCR the text - we'll see. Incidentally, none of the G2DAF stuff links work for me, even with broadband. Pity, as I remember it in the distant past and would like to have seen the articles, just for curiosity. __________________ Mike.

11th Sep 2006, 4:24 pm	#35
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Re: Short Wave Receiver That's helpfull Mike and good quality but only 1/5 pages at my end. If you can get them all up could you send to Frank [Denmark] I wonder and save W Paul the job. Will you still need a photo copy with all these helpfull advanced technology people on stream Paul ? Dave.

11th Sep 2006, 4:32 pm	#36
radioman Heptode Join Date: Apr 2003 Location: Ayr, Ayrshire, UK. Posts: 631	Re: Short Wave Receiver All six pages loaded fine here. Thanks Mike and Graham. Andy __________________ G-QRP #12697

11th Sep 2006, 4:38 pm	#37
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Re: Short Wave Receiver It's obviously a problem at my end, now got 2 pages after a bit of a wait. Perhaps I need more coal in the boiler? Of course I've got the mag anyway but can someone make Frank's day please? Cheers Dave

11th Sep 2006, 7:41 pm	#38
YC-156 Retired Dormant Member Join Date: May 2005 Location: Aarhus, Denmark Posts: 281	Re: Short Wave Receiver Got it. OpenOffice running on FreeBSD can read the doc file in this end. I will give the article a closer look tomorrow. Frank N.

12th Sep 2006, 8:22 am	#39
YC-156 Retired Dormant Member Join Date: May 2005 Location: Aarhus, Denmark Posts: 281	Re: Short Wave Receiver Have given the article a quick look, and I'm afraid this circuit is out of the running, since it isn't a general coverage receiver at all. If you look at the list of bands on page 1, it will be apparent - as the text also states - that this is a ham band receiver with a pair of excessively wide ranges, the higest ones. Secondly the detector is obviously AM only, so no CW or SSB can be received as the receiver stands. Finally I have a list of technical objections. This receiver - like most - is a compromise in many ways. I believe that even for a switched band receiver a much better performer could be built with the same number of valves. Particularly if we are allowed to sprinkle the design with a few more exotic components, like a high frequency crystal filter. But I'm afraid my original comment still stands, so there is probably little reason in listing my objections. There is - to my knowledge - no cookie cutter DIY general coverage receiver designs using valves out there, assuming it should have reasonable performance. Frank N.