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 > Other Discussions > Homebrew Equipment

Notices

Homebrew Equipment A place to show, design and discuss the weird and wonderful electronic creations from the hands of individual members.

Reply
 
Thread Tools
Old 28th Jul 2011, 1:32 pm   #581
Mr_Klaatu
Retired Dormant Member
 
Join Date: Jun 2009
Location: East Coast, Singapore
Posts: 16
Default Re: The "Sussex" Homebrew Valve Tester.

It's a fantastic project - all credit to you Mike.

Mine is still in the build stage, going well so far, finding time is the limiting factor.

I'll post some pics once its done.

What's next
Mr_Klaatu is offline   Reply With Quote
Old 30th Aug 2011, 3:44 pm   #582
mikeydee
Tetrode
 
mikeydee's Avatar
 
Join Date: Aug 2011
Location: Bristol, UK.
Posts: 67
Default Re: Homebrew Valve Tester

Quote:
Originally Posted by swordholder View Post
Over the next few days I will get together a write up and the PCB foil patterns and component layouts, together with setting up instructions and voltage readings from my prototype.
So pleased to find this thread on the VT1.

I would like to try and build one of these after realising that an AVO CT160/VCM 163 is probably going to be so hard to track down.

Could you send me the PCB layout diagrams, please?
mikeydee is offline   Reply With Quote
Old 30th Aug 2011, 10:30 pm   #583
swordholder
Rest in Peace
 
Join Date: Aug 2009
Location: East Preston, Sussex
Posts: 162
Default Re: The "Sussex" Homebrew Valve Tester.

Hi,
There is a PCB layout on post27, if you contact G8UWM Mild Martin I think you will find he may have some PCBs left from a batch he had made.
Ed Dinning also produced a custom transformer.
I know it will be time consuming, but read through all the posts and you will find a wealth of information on the VT1.
Good luck with the build, mine is giving stirling service and has had no failures at all. You will also find several different interpretations of the layout, all looking really good.

Regards

Mike
swordholder is offline   Reply With Quote
Old 1st Sep 2011, 7:16 pm   #584
M0XNA Neil
Tetrode
 
Join Date: Apr 2009
Location: Towcester, Northamptonshire, UK.
Posts: 92
Default Re: The "Sussex" Homebrew Valve Tester.

Mike,
My 'Sussex in a suitcase' is still working well and I am now making an octal adaptor to take wire ended valves.

Neil.
__________________
An engineer makes for a penny what a scientist makes for a pound!
M0XNA Neil is offline   Reply With Quote
Old 15th Sep 2011, 4:04 pm   #585
mikeydee
Tetrode
 
mikeydee's Avatar
 
Join Date: Aug 2011
Location: Bristol, UK.
Posts: 67
Default Re: The "Sussex" Homebrew Valve Tester.

I have started gather parts for my Sussex (transformers, pcbs and meters all ordered). In terms of cases I like the portable approach so will have a look at the alluminium case approach taken by Neun Elf.

My outstanding question is on the rotary switches. Looking at Neun Elf's thumbwheel switches I think this design neatens up the wiring and will give better usability. There seemed to be some doubt about the low current and voltage rating on these type of devices - is there any update on their performance since the VT1 builds using these was some time ago also welcome any supplier suggestions.

MikeyDee
mikeydee is offline   Reply With Quote
Old 15th Sep 2011, 10:17 pm   #586
swordholder
Rest in Peace
 
Join Date: Aug 2009
Location: East Preston, Sussex
Posts: 162
Default Re: The "Sussex" Homebrew Valve Tester.

Hello
Welcome to the builders!!
Although I haven't tried push button switches, I did obtain some from HK on E Bay. My concern with these is not so much with the contact, but with the width of the track connecting the contact with the rear connection strip. It does look as though it is less than 0.5mm wide. Avo contacts on their CTM163 for example are of a much beefier construction, a wide contact wiping on a silver plated rod.
The HK ones I bought, I rigged up a test using 2 in series with a power supply with an EL34 as the load, from memory there was over 0.5v drop across the switch. Not good enough in my opinion.
Let's wait and see what others say.

Regards

Mike
swordholder is offline   Reply With Quote
Old 19th Sep 2011, 10:21 am   #587
davegsm82
Heptode
 
davegsm82's Avatar
 
Join Date: Jan 2004
Location: Blyth, Northumberland, UK.
Posts: 858
Default Re: The "Sussex" Homebrew Valve Tester.

Hi Mike,

I've been watching this thread on the Sussex and I'm quite impressed.

Is there any chance you could condense the design, schematics, build instructions, parts list, operation etc into a few posts? Perhaps even the mods could sticky the thread so it stays clean?

I only ask as its quite difficult to keep track of changes/mods and the general build when its spread across 30 pages of text.

Dave.

Last edited by Mike Phelan; 11th Oct 2011 at 9:55 am. Reason: Corrected typos.
davegsm82 is offline   Reply With Quote
Old 19th Sep 2011, 1:10 pm   #588
RF Burn
Hexode
 
RF Burn's Avatar
 
Join Date: Apr 2008
Location: Ramsgate, Kent, UK.
Posts: 252
Default Re: The "Sussex" Homebrew Valve Tester.

Dave,

Les (Top Cap) has kindly produced an excellent document summarising the Sussex design, this can be found at post #502 which should appear on page 26

Adrian
RF Burn is offline   Reply With Quote
Old 19th Sep 2011, 1:13 pm   #589
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,462
Default Re: The "Sussex" Homebrew Valve Tester.

The handbook is here:-

http://homepage.ntlworld.com/lez/Sus...%20version.doc
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is offline   Reply With Quote
Old 10th Oct 2011, 7:41 pm   #590
loftfullofradio
Retired Dormant Member
 
Join Date: Feb 2009
Location: Manchester UK
Posts: 3
Default Re: The "Sussex" Homebrew Valve Tester.

Hi. I'm just starting my own variant of the Sussex. I have breadboarded the oscillator and found it very temperature sensitive. The o/p rises with temp, does anyone else find this?

Last edited by Mike Phelan; 11th Oct 2011 at 9:57 am. Reason: Corrected typos.
loftfullofradio is offline   Reply With Quote
Old 12th Oct 2011, 7:44 am   #591
swordholder
Rest in Peace
 
Join Date: Aug 2009
Location: East Preston, Sussex
Posts: 162
Default Re: The "Sussex" Homebrew Valve Tester.

Hi,
Welcome to the "Sussex Group", I haven't noticed any great variation with temperature on mine, by how much is it varying?
As you can see there is no temperature compensation. Are you using good quality capacitors, not ceramic, as this may cause the problem.

Regards

Mike
swordholder is offline   Reply With Quote
Old 12th Oct 2011, 1:04 pm   #592
FRANK.C
Heptode
 
FRANK.C's Avatar
 
Join Date: Feb 2006
Location: Roscommon, Ireland
Posts: 736
Default Re: The "Sussex" Homebrew Valve Tester.

Hi loftfullofradio
I have experienced the same phenomenon. See post 460.

Frank
FRANK.C is online now   Reply With Quote
Old 12th Oct 2011, 3:19 pm   #593
RF Burn
Hexode
 
RF Burn's Avatar
 
Join Date: Apr 2008
Location: Ramsgate, Kent, UK.
Posts: 252
Default Re: The "Sussex" Homebrew Valve Tester.

Loftfull,

I am also designing my version of the Sussex VT, my solution to this problem is to use a small cheap 8 pin PIC12F1840 device to generate a rock stable 50Hz sine wave from it's D/A converter, with the supply reduced to 3 - 5 Volts. Works a treat, I will post details when I can find a spare moment...!

Adrian

Last edited by RF Burn; 12th Oct 2011 at 3:22 pm. Reason: Typo
RF Burn is offline   Reply With Quote
Old 12th Oct 2011, 7:03 pm   #594
loftfullofradio
Retired Dormant Member
 
Join Date: Feb 2009
Location: Manchester UK
Posts: 3
Default Re: The "Sussex" Homebrew Valve Tester.

Hi gents.

I find if you set the pot so the oscillator just runs and starts OK, the O/P rise with temp is worse than if it's turned right up. I've breadboarded an osc with a lamp filament in the feedback to stabilise it, however the output has an LF breathing effect. Perhaps due the the thermal time constant of the lamp (about 1Hz). The pic idea sounds good. It should be as stable as the DC supply of the D to A. I will look at post 460.

Thanks for the thoughts so far.

John
loftfullofradio is offline   Reply With Quote
Old 13th Oct 2011, 7:38 pm   #595
loftfullofradio
Retired Dormant Member
 
Join Date: Feb 2009
Location: Manchester UK
Posts: 3
Default Re: The "Sussex" Homebrew Valve Tester.

Sorry. Missed swordholders question. Set to 100mv rms o/p at room temp, rises to over 130mv after 5 mins under my desk lamp, A crude test I know but my shack is in the loft so varies from frost to sauna, winter to summer. The lamp stabilised one rises to about 106mv but needs the lamp fillament shaded or the light warms it through the glass worsenning the drift. As you can see I'm over analysing already. I am awaiting a transformer from Ed so I have plenty of time to worry this problem to death. But if sword holders osc is ok and a few are not, it looks like it may be down to components.
Best wishes to all John
loftfullofradio is offline   Reply With Quote
Old 14th Oct 2011, 9:43 am   #596
PyrusBoy
Triode
 
Join Date: Jun 2011
Location: Gillingham
Posts: 17
Default Re: The "Sussex" Homebrew Valve Tester.

Good Morning all,
I'm not posting very often, but I wonder if anyone can tell me if and where I can obtain transformer and PCB. Interesting project for the winter months as I have 20 or so vintage radios and 1 VT1 Tele, and more to refurb..
Thanks
PyrusBoy is offline   Reply With Quote
Old 14th Oct 2011, 12:17 pm   #597
FRANK.C
Heptode
 
FRANK.C's Avatar
 
Join Date: Feb 2006
Location: Roscommon, Ireland
Posts: 736
Default Re: The "Sussex" Homebrew Valve Tester.

Quote:
Originally Posted by loftfullofradio View Post
it looks like it may be down to components.
Hi John
I have similar temperature variations in my shack.
By heating and cooling each component individually in my build of the original oscillator I found the main culprits to be the transistors TR6 and TR7, but in particular TR7. I tried different transistors in those positions, some did improve the situation, but none were good enough for the temperature variation in my shack.

Frank
FRANK.C is online now   Reply With Quote
Old 14th Oct 2011, 3:41 pm   #598
swordholder
Rest in Peace
 
Join Date: Aug 2009
Location: East Preston, Sussex
Posts: 162
Default Re: The "Sussex" Homebrew Valve Tester.

Quote:
Originally Posted by PyrusBoy View Post
I wonder if anyone can tell me if and where I can obtain transformer and PCB.
Hi,
Transformer available from ED and PCB from Martin. See previous posts for prices and availability

Mike
swordholder is offline   Reply With Quote
Old 14th Oct 2011, 7:15 pm   #599
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,259
Default Re: The "Sussex" Homebrew Valve Tester.

H Gents, transformers are still available if needed.
Pyrus Boy, you have a PM.

Ed
Ed_Dinning is online now   Reply With Quote
Old 5th Nov 2011, 10:26 am   #600
a_strong
Pentode
 
a_strong's Avatar
 
Join Date: Feb 2007
Location: South Yorkshire, UK.
Posts: 134
Unhappy Re: The "Sussex" Homebrew Valve Tester.

Anyone considering using the EBay Chinese thumbwheel switches (as I was!) may be interested in the response to my question: "Dear Sirs - what are the AC and DC voltage and current ratings for this product?".

Quote:

"Thanks for your interest in our item 350502322177. Generally it can be used within DC 24V , and it is 0.5A. Feel free to contact us if you need any assistance. Have a nice day."

End quote.

Alan G3WXI







a_strong is offline   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 4:21 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.