UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Test Gear and Workshop Equipment

Notices

Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders.

Closed Thread
 
Thread Tools
Old 19th Mar 2019, 8:01 pm   #1
ekjdm14
Banned
 
Join Date: Feb 2019
Location: Congleton, Cheshire, UK.
Posts: 609
Default Pye signal generator

I've just taken delivery of the Pye Model 940226 signal generator offered in the classifieds on this forum. Now I've had a closer look at it, I can confirm it's intended for television use & covers frequency ranges from 40-70Mc/s.

As promised to Tom Williams, here's some photos of the internals "as found" (I did get a bit carried away and had already removed some parts hence the valves are just rested in their sockets for the photos, and now labelled, the original markings were coming off so thought best note them)

I'll also have a few questions going forward with this, as I will hopefully have this working in the future & certainly cosmetically renovated. It must have been one expensive bit of kit in it's day, the thickness of the metal shielding alone is about 1/8"! Anyway I'll post some pics now & try and research it a bit, any info/experience of/instructions/manual/schematic etc on the unit would be much appreciated though as there doesn't seem to be a lot out there.

Cheers, Dan.
Attached Thumbnails
Click image for larger version

Name:	IMG_0371.jpg
Views:	291
Size:	65.4 KB
ID:	180194   Click image for larger version

Name:	IMG_0373.jpg
Views:	256
Size:	47.0 KB
ID:	180195   Click image for larger version

Name:	IMG_0374.jpg
Views:	246
Size:	68.2 KB
ID:	180196   Click image for larger version

Name:	IMG_0375.jpg
Views:	240
Size:	90.2 KB
ID:	180197   Click image for larger version

Name:	IMG_0376.jpg
Views:	220
Size:	104.0 KB
ID:	180204  


Last edited by ekjdm14; 19th Mar 2019 at 8:25 pm.
ekjdm14 is offline  
Old 19th Mar 2019, 8:16 pm   #2
ekjdm14
Banned
 
Join Date: Feb 2019
Location: Congleton, Cheshire, UK.
Posts: 609
Default Re: Pye signal generator

So, there are 4 valves total inside the unit, 3 Octal types out in the open and one B7G in the shielded can.

I know three of them, as the markings were readable, the single one next to the transformer and cap is the rectifier, a 6X5GT. Next, inside the can is an EL91 presumably amplifying the signal, then the innermost of the pair is a 6SN7GT.

The leftmost in the photos is, as yet, unknown to me as it's markings had already dissolved Again any info/educated guesses as to what it's likely to be, given the application and other valves would be appreciated. (functioning as an oscillator perhaps?)

Here's some more of the insides as I got it stripped down.

Edit-: wrt pic 5 of the first post (which I tried to get right side up but failed!) I wonder if this points to why it was taken out of service, modulation OK and line OK pencilled on the chassis but no mention of other functions? Also the shielding can had only 2 screws in, so perhaps a fault in there...
Attached Thumbnails
Click image for larger version

Name:	IMG_0377.jpg
Views:	121
Size:	51.7 KB
ID:	180199   Click image for larger version

Name:	IMG_0378.jpg
Views:	124
Size:	84.5 KB
ID:	180200   Click image for larger version

Name:	IMG_0379.jpg
Views:	113
Size:	82.8 KB
ID:	180201   Click image for larger version

Name:	IMG_0380.jpg
Views:	114
Size:	87.2 KB
ID:	180202   Click image for larger version

Name:	IMG_0381.jpg
Views:	118
Size:	70.3 KB
ID:	180203  

ekjdm14 is offline  
Old 19th Mar 2019, 8:23 pm   #3
ekjdm14
Banned
 
Join Date: Feb 2019
Location: Congleton, Cheshire, UK.
Posts: 609
Default Re: Pye signal generator

Last batch of "as found" photos, more to follow as I progress with learning more about this sig-gen & get into the renovation.

Fingers crossed it's a functional restoration rather than just looking nice, it doesn't seem that complicated to work on so as long as the transformers are OK and the valves have some life left I can't see why it wouldn't be possible.

Edit- wrt the voltage selectors, would it likely be better to select 240, or stay at 220 with the +10%, seeing as we tend to run around 248-249VAC fairly consistently here (or even 240 and +10)
Attached Thumbnails
Click image for larger version

Name:	IMG_0382.jpg
Views:	104
Size:	84.4 KB
ID:	180205   Click image for larger version

Name:	IMG_0383.jpg
Views:	125
Size:	82.5 KB
ID:	180206   Click image for larger version

Name:	IMG_0384.jpg
Views:	119
Size:	80.2 KB
ID:	180207   Click image for larger version

Name:	IMG_0386.jpg
Views:	106
Size:	74.0 KB
ID:	180208   Click image for larger version

Name:	IMG_0388.jpg
Views:	107
Size:	54.3 KB
ID:	180209  


Last edited by ekjdm14; 19th Mar 2019 at 8:38 pm.
ekjdm14 is offline  
Old 19th Mar 2019, 8:35 pm   #4
Tom williams
Pentode
 
Tom williams's Avatar
 
Join Date: Jun 2018
Location: Herefordshire, UK.
Posts: 232
Default Re: Pye signal generator

Quote:
Originally Posted by ekjdm14 View Post
Last batch of "as found" photos, more to follow as I progress with learning more about this sig-gen & get into the renovation.
That's good that it arrived in good condition, any chance of seeing the inside?
Tom williams is offline  
Old 19th Mar 2019, 8:39 pm   #5
ekjdm14
Banned
 
Join Date: Feb 2019
Location: Congleton, Cheshire, UK.
Posts: 609
Default Re: Pye signal generator

See above posts It was in pieces within an hour of arrival! (maybe the link I sent you only showed the last post?)
ekjdm14 is offline  
Old 19th Mar 2019, 9:24 pm   #6
HamishBoxer
Dekatron
 
HamishBoxer's Avatar
 
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,923
Default Re: Pye signal generator

Well,that is two of us as I have one sat here, though not as yet ever powered up!
__________________
G8JET BVWS Archivist and Member V.M.A.R.S
HamishBoxer is offline  
Old 19th Mar 2019, 10:35 pm   #7
MotorBikeLes
Nonode
 
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
Posts: 2,346
Default Re: Pye signal generator

Years ago I had a Cossor TV alignment generator, probably similar range to that (Model 1320 I think). If you think about it, that 40-70MCs range nicely covers FM on 1st harmonic. I learned all about FM alignment using that with a 'scope.
I suspect that would be more use than the Cossor, so make the best of it. You need a circuit and instructions.
Les.
MotorBikeLes is offline  
Old 20th Mar 2019, 11:59 am   #8
ekjdm14
Banned
 
Join Date: Feb 2019
Location: Congleton, Cheshire, UK.
Posts: 609
Default Re: Pye signal generator

Quote:
Originally Posted by HamishBoxer View Post
Well,that is two of us as I have one sat here, though not as yet ever powered up!
Definitely, definitely not powering this one up until I've gone through it either! I think it's likely to have at least one fault and has seen a little weather, but looks clean enough inside. The build quality is just staggering, and the fit & finish means the wet stuff has largely stayed out of the chassis thankfully.

Will be entertaining to find info on it and try and get it functioning/find something to use it on. The point about using the 1st harmonic is a great thought & hadn't even crossed my mind (long road of learning ahead as far as radio goes!) but it does bring the possibility of it being of use on my Ekco VHF set back within reason

Thanks for the replies.
ekjdm14 is offline  
Old 20th Mar 2019, 1:49 pm   #9
ms660
Dekatron
 
ms660's Avatar
 
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
Default Re: Pye signal generator

The modulation frequencies should be 400Hz (sound and frame) and 60kHz (line)

Lawrence.
ms660 is offline  
Old 22nd Mar 2019, 11:27 pm   #10
Tom williams
Pentode
 
Tom williams's Avatar
 
Join Date: Jun 2018
Location: Herefordshire, UK.
Posts: 232
Default Re: Pye signal generator

Quote:
Originally Posted by ekjdm14 View Post
Will be entertaining to find info on it and try and get it functioning/find something to use it on. The point about using the 1st harmonic is a great thought & hadn't even crossed my mind (long road of learning ahead as far as radio goes!) but it does bring the possibility of it being of use on my Ekco VHF set back within reason
If you look on my other forums, you'll find one that says "wg Pye?", Click on it and scroll down, you'll see a link to a PDF of the manual.

Quote:
Originally Posted by ekjdm14 View Post
As promised to Tom Williams, here's some photos of the internals "as found" (I did get a bit carried away and had already removed some parts hence the valves are just rested in their sockets for the photos, and now labelled, the original markings were coming off so thought best note them)
Thank you for taking these, I was unable to take it apart due to the weight on my recently corrected scoliosis.
Tom williams is offline  
Old 8th May 2019, 6:56 pm   #11
ekjdm14
Banned
 
Join Date: Feb 2019
Location: Congleton, Cheshire, UK.
Posts: 609
Default Re: Pye signal generator

Coming back to this after a while, prompted in part by acquiring an AM radio alignment generator so thought what better time to get on with sorting my vintage test gear.

So far, 4 waxies and one electrolytic have been evicted & there remain a few "metalmite" caps which I believe are in fact wax caps in a metal case(?) so will have to go if that's right.

The other electrolytics I hold some hope of reforming & will attempt this shortly.

Aside from the obvious caps, I've given the switches a clean, scraped corrosion from the case & most impressively (for me, since I hardly have a jeweller's touch!) got the meter working again. The glass had been pushed back bending the needle & allowing all sorts of dirt into the movement which was sticking. Some very careful, and I will admit lucky, cleaning of the moving coil meter's inner guts and detangling the clockspring which was scary, it's at least working to the point where I can learn to "work around" it's foibles and may give it a more thorough going over one day.

Later on this evening, I hope to tentatively apply power through the variac & will report back on this if I have the chance. For now, cap reforming and searching for some operating instructions are the priorities. (I note Tom mentioned the manual above, but not sure whereabouts to find that nor if it's a service manual or operators.).

Cheers,
ekjdm14 is offline  
Old 8th May 2019, 9:03 pm   #12
ekjdm14
Banned
 
Join Date: Feb 2019
Location: Congleton, Cheshire, UK.
Posts: 609
Default Re: Pye signal generator

Further to my last, the sig. gen. is now in working order (at least in the Sound mode, only tested it on harmonics of FM broadcast frequencies as no TV in the dining room/workshop).

So far impressions are, the level meter sticks as I expected but only higher in the range. Frequency appears to be accurate as I can override Radio 2 on 91Mhz at around 45.5 on the scale, and same for Classic FM on 101.1 with the generator set to 50.5Mhz so it's looking hopeful. Tomorrow hopefully will get time to play around and see if it's capable of generating any image on a TV.

The only potential problem cap is a 16uF at 500v which still got a little warm after running for 15 minutes but I'll keep tabs on it and see whether I need to order a replacement. Once it's been tested on a TV and I'm happy with the electronics side of things I'll start looking at cleaning it and making it a bit prettier although it's not in horrible condition anyway, just a case of cleaning up rusty screw heads, polishing the handle and possibly locating a replacement selector knob and meter.
ekjdm14 is offline  
Old 9th May 2019, 5:10 pm   #13
ekjdm14
Banned
 
Join Date: Feb 2019
Location: Congleton, Cheshire, UK.
Posts: 609
Default Re: Pye signal generator

OK couple more photos of the signal generator in "use" (inverted commas since it's working on a weak harmonic of it's actual frequency somewhere in the mid 4-500MHz area since my TV only does system I, hence attenuator fully home and carrier fully up I just about have enough signal to show frame working.).

Also while in the front room I hooked it to my Technics digital FM tuner and confirmed the scale is pretty darned accurate, harmonic appearing on 87.5MHz with pointer just under 44MHz and further check at 100.0MHz and the pointer exactly on 50MHz.

I now need an old VHF set to test properly since not sure if Circle Window or Line are in fact working properly as they don't show on the 1982-ish Guinea Pig B&O 8802. Overall though not a bad start & hopefully Tom will be pleased to see progress on this too.
Attached Thumbnails
Click image for larger version

Name:	20190509_161318.jpg
Views:	134
Size:	55.7 KB
ID:	182778   Click image for larger version

Name:	20190509_161350.jpg
Views:	133
Size:	56.7 KB
ID:	182779  
ekjdm14 is offline  
Old 12th May 2019, 5:58 pm   #14
Tom williams
Pentode
 
Tom williams's Avatar
 
Join Date: Jun 2018
Location: Herefordshire, UK.
Posts: 232
Default Re: Pye signal generator

Hello there!
I am extremely pleased to see that you have got it working, don't know why it was in the shed at the end of a garden?
Tom williams is offline  
Old 13th May 2019, 8:32 pm   #15
ekjdm14
Banned
 
Join Date: Feb 2019
Location: Congleton, Cheshire, UK.
Posts: 609
Default Re: Pye signal generator

Most likely just through lack of use, the system it was designed to work on was 405 line which I believe did run until mid 1980's but probably not a huge volume of work on TV's supporting that standard after the mid 60's I should imagine.

That and the size/weight of the thing meaning it's not all that convenient to lug around. Probably was held onto by it's owner because they remembered how expensive it had been to buy (and it really must have cost a huge amount given the quality of the thing) & they just couldn't bring themselves to dispose of it even though it wasn't being used.

Considering how large and solid it is, it'll probably be mainly a display piece for me but it's nice to have something working the way it's intended. I just need an old enough TV now to properly test it!
ekjdm14 is offline  
Old 14th May 2019, 11:32 pm   #16
m0cemdave
Octode
 
Join Date: Feb 2009
Location: Bletchley, Buckinghamshire, UK.
Posts: 1,205
Default Re: Pye signal generator

If you think that's too big and solid, you should be glad it isn't the "Service Workshop Rack" which combined the signal generator with a component measurement bridge.
About 3ft high and awkward to move around, though of course intended to stay put in the workshop.
I think HamishBoxer has one...
m0cemdave is offline  
Old 17th May 2019, 8:08 am   #17
Tom williams
Pentode
 
Tom williams's Avatar
 
Join Date: Jun 2018
Location: Herefordshire, UK.
Posts: 232
Default Re: Pye signal generator

Quote:
Originally Posted by ekjdm14 View Post
Coming back to this after a while, prompted in part by acquiring an AM radio alignment generator so thought what better time to get on with sorting my vintage test gear.

So far, 4 waxies and one electrolytic have been evicted & there remain a few "metalmite" caps which I believe are in fact wax caps in a metal case(?) so will have to go if that's right.

The other electrolytics I hold some hope of reforming & will attempt this shortly.

Aside from the obvious caps, I've given the switches a clean, scraped corrosion from the case & most impressively (for me, since I hardly have a jeweller's touch!) got the meter working again. The glass had been pushed back bending the needle & allowing all sorts of dirt into the movement which was sticking. Some very careful, and I will admit lucky, cleaning of the moving coil meter's inner guts and detangling the clockspring which was scary, it's at least working to the point where I can learn to "work around" it's foibles and may give it a more thorough going over one day.

Later on this evening, I hope to tentatively apply power through the variac & will report back on this if I have the chance. For now, cap reforming and searching for some operating instructions are the priorities. (I note Tom mentioned the manual above, but not sure whereabouts to find that nor if it's a service manual or operators.).

Cheers,
Not the manual but part of a magazine its in:
https://www.vintage-radio.net/forum/...69&postcount=4
Tom williams is offline  
Old 17th May 2019, 8:30 am   #18
HamishBoxer
Dekatron
 
HamishBoxer's Avatar
 
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,923
Default Re: Pye signal generator

"HamishBoxer" does indeed have that Pye Service Rack,and it certainly is a beastie. Goodness knows how much when new, I think I gave no more than £30 for this one and must get it sorted in the near future.

PS I also have the one being discussed as well!
__________________
G8JET BVWS Archivist and Member V.M.A.R.S
HamishBoxer is offline  
Old 21st May 2019, 8:17 pm   #19
ekjdm14
Banned
 
Join Date: Feb 2019
Location: Congleton, Cheshire, UK.
Posts: 609
Default Re: Pye signal generator

Yes I seem to recall glancing through a thread on here about the Service Rack whilst researching the 940226. One other thing about it's mass given the quality & value of the things, they'd have taken a very dedicated thief to liberate them from a workshop back when they were in active professional service.

HamishBoxer, if you have 405 TV's in need of service and get a spare couple of hours it'd be well worth the effort of getting yours going IMO, it's a fantastic bit of equipment and would love to see one inputting to a set where it's full capabilities can be made use of. (To the point where I am actually considering the acquisition of a suitable TV myself, even though my main CRT passion is for '70s-'80s colour sets! Shame it's not as much help with my latest toy, an '87 Logik with very few hours but alignment issues)
ekjdm14 is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 2:58 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.