Homebrew ESR meter - UK Vintage Radio Repair and Restoration Discussion Forum

Guitarist28 · 5th Oct 2010, 7:03 pm

I had intended to build one of these a good while back using the information kindly provided by David G4EBT in a 'parallel' build with Josh Ward, but like all good intentions it went on the back burner as other projects became a higher priority. Anyway, Josh kick started me back into action following 'are we going to build this email??'.

I decided to make our pcbs using the 'press & peel method' which i think works very well. I etched the boards using sodium persulphate having always used ferric chloride in the past. This method appears much more controllable so I shall use this again in future.

Once checked for faults, shorts and possible broken tracks, the board was populated following the build information Davids posts on the forum (homebrew section). Like all builds the unit didn't work to start with and after some fault finding and some solid help and advice from David, the faults were traced and corrected. Most problems apperaed to occur with the Q1 2N2222 as I had purchased plastic bodied (T092) and not metal cased (T018) versions which do appear to have the collector and emitter reversed. Anyway a swap to a metal cased T018 2N2222 appeared to solve the problem.

I have attached some oscilloscope traces to show the oscillation from IC1 and then to the base of q1 and the signal amplified at the collector of q1.
I have also attached a picture of the unit showing fsd with a good 1000uF 35v electro cap and the reading with a 10R resistor - the scale is suprising accurate.

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I really can't thank David G4EBT enough for his help, guidance and patience enough especially with the using my 'scope to which I really did learn a lot.
If I can build one of these then I am sure that anyone can!

Rob

Diabolical Artificer · 6th Oct 2010, 9:01 am

Nice one Rob,i like your panel meter,did you get it like that or did you modify a uA type?Building one myself,but as you found Im having teething troubles.Getting there.Andy.

Guitarist28 · 6th Oct 2010, 9:33 pm

Hi Andy,
Thanks for your response.
The meter used was the one indicated in Davids thread (see below) and I printed and affixed the scale to convert to Ohms.

Regards

Rob

The meter that I used was - as I stated, from (aptly named!) ESR Electronics, order code 124-116 'Analogue meter - 0-50uA'. It has an internal resistance of 6,500 Ohms.
The current price of the meter is £5.31 + P&P and VAT.

http://www.esr.co.uk/electronics/pro..._testequip.htm

Diabolical Artificer · 7th Oct 2010, 7:58 am

I have got the meter from ESR(took quite a while,they had to order some in).How did you design/print the label Rob,its very well done?Lastly,have you any extra PCB,s?Ive done mine on veroboard to Top Cap,s spec,s,but have enough components to make another.I would happily remunerate you for your time/materials etc,Andy.

milairuk · 7th Oct 2010, 12:35 pm

Quote:

Originally Posted by magnetic

I have got the meter from ESR(took quite a while,they had to order some in).How did you design/print the label Rob,its very well done?

If it's any help I remove the existing scale, scan it on my scanner and then use Paint Shop Pro to delete unwanted markings and then put back what I need. Then print onto good quality photopaper and stick it over the original

John

JoshWard · 7th Oct 2010, 5:28 pm

Forget Rob's rubbish ESR meter....this is what one should look like!

milairuk · 7th Oct 2010, 7:40 pm

Well here's mine - with the dial made as described above

Guitarist28 · 7th Oct 2010, 8:26 pm

Josh,
Well done - I'm so pleased for you that its working

Regards

Rob

Diabolical Artificer · 7th Oct 2010, 9:07 pm

Thanks Rob for that info.Rob,s got you beat Josh,an old margerine tub,and black feltip.....erm...: ),A

Herald1360 · 7th Oct 2010, 11:04 pm

Josh's has a certain "Je ne sais quoi" about it. Not too sure I'd want to, really

JoshWard · 8th Oct 2010, 2:15 pm

Margarine tub?! I'll have you know that is one of RS' finest grey plastic boxes!

At the end of the day it's a functional cheap item, and my first ever home built electrical equipment so I'm more than happy with it.

Naturally I too had several problems, first the voltage regulator was faulty and then after it still didn't work Rob told me I was meant to solder the terminal tags on the PCB

I must say a huge amount of thanks to Rob, without whom this project would still be long way down the to do list.

Josh.

JoshWard · 19th Jun 2011, 8:56 pm

Thanks to a bit of Sunday evening boredom it now looks resplendent in a new case complete with a small neon and a flashier knob

Josh.

Guitarist28 · 19th Jun 2011, 11:53 pm

Hi Josh,
That looks the business now, well done sir.

Regards

Rob

JoshWard · 20th Jun 2011, 11:53 pm

Thankyou Sir

Certainly beats the previous 'effort'!

5th Oct 2010, 7:03 pm	#1
Guitarist28 Heptode Join Date: Dec 2009 Location: Hockley, Essex, UK. Posts: 575	Homebrew ESR meter I had intended to build one of these a good while back using the information kindly provided by David G4EBT in a 'parallel' build with Josh Ward, but like all good intentions it went on the back burner as other projects became a higher priority. Anyway, Josh kick started me back into action following 'are we going to build this email??'. I decided to make our pcbs using the 'press & peel method' which i think works very well. I etched the boards using sodium persulphate having always used ferric chloride in the past. This method appears much more controllable so I shall use this again in future. Once checked for faults, shorts and possible broken tracks, the board was populated following the build information Davids posts on the forum (homebrew section). Like all builds the unit didn't work to start with and after some fault finding and some solid help and advice from David, the faults were traced and corrected. Most problems apperaed to occur with the Q1 2N2222 as I had purchased plastic bodied (T092) and not metal cased (T018) versions which do appear to have the collector and emitter reversed. Anyway a swap to a metal cased T018 2N2222 appeared to solve the problem. I have attached some oscilloscope traces to show the oscillation from IC1 and then to the base of q1 and the signal amplified at the collector of q1. I have also attached a picture of the unit showing fsd with a good 1000uF 35v electro cap and the reading with a 10R resistor - the scale is suprising accurate. I really can't thank David G4EBT enough for his help, guidance and patience enough especially with the using my 'scope to which I really did learn a lot. If I can build one of these then I am sure that anyone can! Rob

6th Oct 2010, 9:01 am	#2
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,667	Re: Homebrew ESR meter Nice one Rob,i like your panel meter,did you get it like that or did you modify a uA type?Building one myself,but as you found Im having teething troubles.Getting there.Andy. __________________ Curiosity hasn't killed this cat...so far.

6th Oct 2010, 9:33 pm	#3
Guitarist28 Heptode Join Date: Dec 2009 Location: Hockley, Essex, UK. Posts: 575	Re: Homebrew ESR meter Hi Andy, Thanks for your response. The meter used was the one indicated in Davids thread (see below) and I printed and affixed the scale to convert to Ohms. Regards Rob The meter that I used was - as I stated, from (aptly named!) ESR Electronics, order code 124-116 'Analogue meter - 0-50uA'. It has an internal resistance of 6,500 Ohms. The current price of the meter is £5.31 + P&P and VAT. http://www.esr.co.uk/electronics/pro..._testequip.htm

7th Oct 2010, 7:58 am	#4
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,667	Re: Homebrew ESR meter I have got the meter from ESR(took quite a while,they had to order some in).How did you design/print the label Rob,its very well done?Lastly,have you any extra PCB,s?Ive done mine on veroboard to Top Cap,s spec,s,but have enough components to make another.I would happily remunerate you for your time/materials etc,Andy. __________________ Curiosity hasn't killed this cat...so far.

7th Oct 2010, 5:28 pm	#6
JoshWard Octode Join Date: Dec 2005 Location: Near Stowmarket, Suffolk, UK. Posts: 1,962	Re: Homebrew ESR meter Forget Rob's rubbish ESR meter....this is what one should look like! Attached Thumbnails

7th Oct 2010, 7:40 pm	#7
milairuk Pentode Join Date: May 2005 Location: Chelmsford, Essex, UK. Posts: 150	Re: Homebrew ESR meter Well here's mine - with the dial made as described above Attached Thumbnails

7th Oct 2010, 8:26 pm	#8
Guitarist28 Heptode Join Date: Dec 2009 Location: Hockley, Essex, UK. Posts: 575	Re: Homebrew ESR meter Josh, Well done - I'm so pleased for you that its working Regards Rob

7th Oct 2010, 9:07 pm	#9
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,667	Re: Homebrew ESR meter Thanks Rob for that info.Rob,s got you beat Josh,an old margerine tub,and black feltip.....erm...: ),A __________________ Curiosity hasn't killed this cat...so far.

7th Oct 2010, 11:04 pm	#10
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Homebrew ESR meter Josh's has a certain "Je ne sais quoi" about it. Not too sure I'd want to, really __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

8th Oct 2010, 2:15 pm	#11
JoshWard Octode Join Date: Dec 2005 Location: Near Stowmarket, Suffolk, UK. Posts: 1,962	Re: Homebrew ESR meter Margarine tub?! I'll have you know that is one of RS' finest grey plastic boxes! At the end of the day it's a functional cheap item, and my first ever home built electrical equipment so I'm more than happy with it. Naturally I too had several problems, first the voltage regulator was faulty and then after it still didn't work Rob told me I was meant to solder the terminal tags on the PCB I must say a huge amount of thanks to Rob, without whom this project would still be long way down the to do list. Josh.

19th Jun 2011, 8:56 pm	#12
JoshWard Octode Join Date: Dec 2005 Location: Near Stowmarket, Suffolk, UK. Posts: 1,962	Re: Homebrew ESR meter Thanks to a bit of Sunday evening boredom it now looks resplendent in a new case complete with a small neon and a flashier knob Josh. Attached Thumbnails

19th Jun 2011, 11:53 pm	#13
Guitarist28 Heptode Join Date: Dec 2009 Location: Hockley, Essex, UK. Posts: 575	Re: Homebrew ESR meter Hi Josh, That looks the business now, well done sir. Regards Rob

20th Jun 2011, 11:53 pm	#14
JoshWard Octode Join Date: Dec 2005 Location: Near Stowmarket, Suffolk, UK. Posts: 1,962	Re: Homebrew ESR meter Thankyou Sir Certainly beats the previous 'effort'!