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 16th Jan 2010, 4:51 pm   #81
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
Default Re: The "Sussex" Homebrew Valve Tester.

Hi Mike, 35V at 50mA it is.
To keep the cost down I will make it a frame type with flying, colour coded leads. Leads will come out of one side only so it can be "drop through " mounted.
Angle brackets can then be used for upright mounting.
I'll post some pics when it is complete. Can you PM me your address please Mike.

Ed
Ed_Dinning is offline   Reply With Quote
Old 16th Jan 2010, 4:52 pm   #82
Top Cap
Octode
 
Top Cap's Avatar
 
Join Date: Mar 2006
Location: Watford, Hertfordshire, UK.
Posts: 1,270
Default Re: The "Sussex" Homebrew Valve Tester.

Sounds super Ed, for safety - will the transformer have an internal screen or are you using split bobbins?
Les
__________________
Whether the Top Cap is Grid or Anode - touching it will give you a buzz either way!
Top Cap is offline   Reply With Quote
Old 16th Jan 2010, 4:56 pm   #83
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
Default Re: The "Sussex" Homebrew Valve Tester.

Hi Les, it will be a screen, split bobbins give poor regulation

Ed
Ed_Dinning is offline   Reply With Quote
Old 16th Jan 2010, 5:07 pm   #84
Top Cap
Octode
 
Top Cap's Avatar
 
Join Date: Mar 2006
Location: Watford, Hertfordshire, UK.
Posts: 1,270
Default Re: The "Sussex" Homebrew Valve Tester.

Wow Ed I never knew that. Now I know why Lab Power Supplies always seem to use the normal (if I may call it that) type of single over wound bobbin.
Cheers
Les
__________________
Whether the Top Cap is Grid or Anode - touching it will give you a buzz either way!
Top Cap is offline   Reply With Quote
Old 19th Jan 2010, 9:53 pm   #85
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
Default Re: The "Sussex" Homebrew Valve Tester.

Hi Gents, here are some pics of the prototype transformer ready to go to Mike. It's not impregnated or over taped as it may need mods.
Size is 3 3/4" *3 1/8" and a 1 1/2" stack. It is 3" over the belly. FC's are 3 1/8" * 2 1/2"

Ed
Attached Thumbnails
Click image for larger version

Name:	100_0134.jpg
Views:	1020
Size:	61.2 KB
ID:	31907   Click image for larger version

Name:	100_0135.jpg
Views:	882
Size:	60.2 KB
ID:	31908  
Ed_Dinning is offline   Reply With Quote
Old 24th Jan 2010, 1:16 pm   #86
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
Default Re: The "Sussex" Homebrew Valve Tester.

Hi Gents, costings etc now completed on this transformer.
It works out at £50 including UK postage (collect from Newcastle if you want a discount).

Could those who expressed interest please re-confirm by PM and any other interested parties also. I will then order the materials and the transformers will be available in about 3 to 4 weeks time.

Best regards, Ed
Ed_Dinning is offline   Reply With Quote
Old 24th Jan 2010, 2:26 pm   #87
Andymic
Retired Dormant Member
 
Join Date: Jan 2010
Location: Harrow, London, UK.
Posts: 78
Default Re: The "Sussex" Homebrew Valve Tester.

Hi,

I'm new to both this forum and this thread.

This looks fascinating...

Will there be a PCB manufactured for a group buy?

Andy
Andymic is offline   Reply With Quote
Old 25th Jan 2010, 12:50 am   #88
G8UWM-MildMartin
Heptode
 
Join Date: Jan 2004
Location: Stockport, Greater Manchester, UK.
Posts: 826
Default Re: The "Sussex" Homebrew Valve Tester.

Yes!

In about 3 weeks.

It will be 1.6mm fibreglass,
I've ordered 50-off etched only from P&M services, undrilled, to keep the cost down.

Price yet to be determined to allow a royalty for Mike, (but likely to be nearer £10 inclusive than free or £20...) and, hopefully, cheaper than buying the necessary photo-resist board & chemicals for a 1-off.

Martin.

Last edited by Dave Moll; 25th Jan 2010 at 4:19 pm. Reason: unnecessary quote removed
G8UWM-MildMartin is online now   Reply With Quote
Old 25th Jan 2010, 12:54 am   #89
Andymic
Retired Dormant Member
 
Join Date: Jan 2010
Location: Harrow, London, UK.
Posts: 78
Smile Re: The "Sussex" Homebrew Valve Tester.

In that case you can count me in for a PCB and transformer.

Nice one !!
Andymic is offline   Reply With Quote
Old 25th Jan 2010, 9:56 pm   #90
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
Default Re: The "Sussex" Homebrew Valve Tester.

Hi Gents, when you PM me for transformers please include your postal address. I'll let you know when they are being sent off and you can then pay me by cash or cheque,

Best regards, Ed
Ed_Dinning is offline   Reply With Quote
Old 25th Jan 2010, 10:25 pm   #91
Top Cap
Octode
 
Top Cap's Avatar
 
Join Date: Mar 2006
Location: Watford, Hertfordshire, UK.
Posts: 1,270
Default Re: The "Sussex" Homebrew Valve Tester.

Swordholder, could I get away with just two front panel meters?
I happen to have two Lascar single hole mounting panel meters, could I switch one to measure Anode/Screen current and the other Grid V/Gm or would this be inconvenient in practice?
Les
__________________
Whether the Top Cap is Grid or Anode - touching it will give you a buzz either way!
Top Cap is offline   Reply With Quote
Old 25th Jan 2010, 10:46 pm   #92
swordholder
Rest in Peace
 
Join Date: Aug 2009
Location: East Preston, Sussex
Posts: 162
Default Re: The "Sussex" Homebrew Valve Tester.

Hi Top Cap,
There is no reason why you have to have 3 meters. You can switch, but bear in mind that the GM meter measures AC millivolts to a resolution of 0.1mV.
Obviously the meter sensitivity will have to taken into consideration, again the anode current meter is a 199.9mv DC meter with a resolution of 0.1mV.
I don't know the Lascar meters, are they analogue or digital.
I used the 3 meters because (a) they dont need any switching and (b) they are relatively cheap at around £6 each including carriage on E Bay (see my previous posts for address).
If you do use the Lascar meters, you may have to alter values of resistors around the circuit.

Regards

Mike
swordholder is offline   Reply With Quote
Old 25th Jan 2010, 11:47 pm   #93
Andymic
Retired Dormant Member
 
Join Date: Jan 2010
Location: Harrow, London, UK.
Posts: 78
Default Re: The "Sussex" Homebrew Valve Tester.

Mike,

Is there any chance that you could produce a BOM for this.

Regards

Andy
Andymic is offline   Reply With Quote
Old 26th Jan 2010, 9:36 am   #94
swordholder
Rest in Peace
 
Join Date: Aug 2009
Location: East Preston, Sussex
Posts: 162
Default Re: The "Sussex" Homebrew Valve Tester.

Andy,
I don't have a BOM, but the component values are all on the ciruit I published, any additions has been covered in my subsequent postings.
If you have any query let me know and I will try to answer your query
.

Regards
Mike
swordholder is offline   Reply With Quote
Old 26th Jan 2010, 3:57 pm   #95
Andymic
Retired Dormant Member
 
Join Date: Jan 2010
Location: Harrow, London, UK.
Posts: 78
Default Re: The "Sussex" Homebrew Valve Tester.

Mike,

Yes, I've gleamed what I can from the published threads.

I guess it's just things such as resistor ratings (1/8w, 1/4w etc) and capacitor voltage ratings, part numbers of the switches you used, etc. etc.

If I can get all the info I'd be happy to put a BOM together that anyone can refer to.
Andymic is offline   Reply With Quote
Old 26th Jan 2010, 8:39 pm   #96
Andymic
Retired Dormant Member
 
Join Date: Jan 2010
Location: Harrow, London, UK.
Posts: 78
Default Re: The "Sussex" Homebrew Valve Tester.

OK,

I have put together a basic BOM for this.
Things I am missing......

Valve bases
Most Switches
Resistor ratings
Capacitor voltage ratings

Feel free to tell me what I've done wrong and suggest ratings, switches etc.

Andy

Link to BOM

http://spreadsheets.google.com/ccc?k...pfMlE&hl=en_GB
Andymic is offline   Reply With Quote
Old 27th Jan 2010, 12:14 am   #97
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,737
Default Re: The "Sussex" Homebrew Valve Tester.

Quote:
Originally Posted by swordholder View Post
I used the 3 meters because (a) they dont need any switching and (b) they are relatively cheap at around £6 each including carriage on E Bay (see my previous posts for address).
If you do use the Lascar meters, you may have to alter values of resistors around the circuit.
That supplier presently shows no stock on e-bay, as does a firm I've used called Virtual Village. Maybe that's a temporary state of affairs. I hope so - these are great little meters, and as cheap if not cheaper than analogue meters, and being backlit, are nice and clear.

David,
G4EBT
David G4EBT is online now   Reply With Quote
Old 27th Jan 2010, 12:45 am   #98
MichaelR
Retired Dormant Member
 
MichaelR's Avatar
 
Join Date: Mar 2006
Location: Sheffield, South Yorkshire, UK.
Posts: 1,587
Default Re: The "Sussex" Homebrew Valve Tester.

Dave,

Asia Engineer on Ebay have them in stock, I ordered a set today.

http://cgi.ebay.com/ws/eBayISAPI.dll...m=370325100729


Regards
Mike
MichaelR is offline   Reply With Quote
Old 27th Jan 2010, 1:16 am   #99
G8UWM-MildMartin
Heptode
 
Join Date: Jan 2004
Location: Stockport, Greater Manchester, UK.
Posts: 826
Default Re: The "Sussex" Homebrew Valve Tester.

Andy,
Excellent!
A starter:
Add 2 1N4007s if using Ed's transformer, to make a bridge with D1 & D2,
D8-11 could be any 1N400x,
R2 dissipates about 0.75W, so perhaps a 2-watter, stood off the PCB?
Martin.
G8UWM-MildMartin is online now   Reply With Quote
Old 27th Jan 2010, 9:31 am   #100
swordholder
Rest in Peace
 
Join Date: Aug 2009
Location: East Preston, Sussex
Posts: 162
Default Re: The "Sussex" Homebrew Valve Tester.

Andy,
The majority of the resistors (apart from the one Martin mentioned) are 0.6w MF fron Rapid electronics
Switches are
2 x 1p 12w Make before Break rotary switches (Rapid Electronics 79-0100) Anode/G2 volts
1 x 3p 4w rotary switch (Rapid Electronics 79-0222) Function switch
10 x 1p 12w rotary switch (Rapid Electronics 79-0220)
(A1/A2 sel + pin selectors)
Relays are
Relays 2 x 48v low profile 8A (Rapid Electronics 60-4854 or similar
LEDS
LED1 Standard green LED
LED on relay board Standard Green LED
LED2 LED3 Low Current red LED (Rapid Electronics 56-0430 or similar
Hope this helps.

Regards
Mike
swordholder is offline   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 11:10 am.


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.