marconi 2022e problem - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Skywave · 14th Sep 2006, 6:23 pm

Request to Moderator.

This is a really informative Thread. May I request that when it "goes cold" it is archived? Seems to be a pity if it goes to waste.

Thanks.

Al.

jazzy · 16th Sep 2006, 12:38 pm

Helo there

I think i will buy a esr meter to make it easy to check the caps,

and i will let you know the out come.

jazzy · 20th Sep 2006, 7:36 pm

hello there

well heres the story so far i have tried an atias esr60 meter and this is ok,
but i can not test the the smaller caps with this.
Is there any other way of testing these? also a have found that some
of the caps have been changed in the other meter what i have got working to diode

harrybeadlebaum · 22nd Sep 2006, 6:40 pm

Hi Jazzy,

On the subject of ESR, have you seen this old thread?:

https://www.vintage-radio.net/forum/...&highlight=esr

If you've not already seen it, have a look at Jim's "scope method" for checking the ESR of capacitors

Regards,

Harry.

jazzy · 22nd Sep 2006, 10:17 pm

Hi mate

I tried this method but to no joy,
the way i connected it up was to place a BNC T piece on the output to my
signal gen with one side of the T piece having a lead with croc clips on it (to test the caps) and the other side of the T piece having a lead going to another T piece what is connected to my scope with a 50 ohm load on the other side.

I found this method on the internet to , I have the gen set to 100hz on square wave

jim_beacon · 22nd Sep 2006, 10:25 pm

Quote:

Originally Posted by jazzy

I have the gen set to 100hz on square wave

You need to increase the frequency to around 100kHz!, otherwise, the reactance of the capacitor swamps the ESR.

The idea is that the ESR swamps the reactance, which, at 100kHz, it will for values of capacitor >1uF.

I generally set the signal generator 100mV pk-to-pk output (to low to turn on transistor junctions) at 100kHz, the adjust the scope for a full height trace. Adjust the timebase so the screen looks like a solid block of colour. Connecting a good capacitor should reduce the trace to a thin line, one with high ESR will have little effect (if you have a spreadsheet program, you can calculate the % reduction in trace height for various values of ESR).

Jim.

JoOngle · 26th Nov 2006, 12:25 am

Interesting Thread!

I've just purchased an Marconi 2022a myself and while it works just fine
I might just look to change those old caps myself to "prevent" the
wear and tear of the powersupply with such caps.

It was exactly the same problem with my HP 8590a Spectrum Analyzer,
blown 6.8 uF caps all over the Analog Interface shorting the -15v, after
replacing (all) of those with fresh 10uF's - problem gone - works like
a dream and have done so for a good while.

Hm.. wonder if the 2022a and 2022e are somewhat identical,
same design...same display....same buttons...hmm.

johngul · 5th Jul 2007, 6:19 pm

I have a 2022A that i'm trying to repair. The previous owner has messed around with IC15 and the matched schottky diodes on the lowest board (AB1)in an attempt to repair the output level (which is incorrect).

I have the 2022A manual but it is missing chapter 5 (maintenance). I found the 2022E manual in PDF format but am suspecting that the AB1/2 board is different on the two 2022's. Can anyone confirm this?

Specifically, i'm getting wrong voltages around IC15 when switching between 62 and 63 MHz (positive voltage is negative and vice versa when going over the 62.5 MHz limit).

14th Sep 2006, 6:23 pm	#21
Skywave Rest in Peace Join Date: Jun 2006 Location: Chard, South Somerset, UK. Posts: 7,457	Re: marconi 2022e problem Request to Moderator. This is a really informative Thread. May I request that when it "goes cold" it is archived? Seems to be a pity if it goes to waste. Thanks. Al.

16th Sep 2006, 12:38 pm	#22
jazzy Retired Dormant Member Join Date: Aug 2006 Location: Essex, UK. Posts: 64	Re: marconi 2022e problem Helo there I think i will buy a esr meter to make it easy to check the caps, and i will let you know the out come.

20th Sep 2006, 7:36 pm	#23
jazzy Retired Dormant Member Join Date: Aug 2006 Location: Essex, UK. Posts: 64	Re: marconi 2022e problem hello there well heres the story so far i have tried an atias esr60 meter and this is ok, but i can not test the the smaller caps with this. Is there any other way of testing these? also a have found that some of the caps have been changed in the other meter what i have got working to diode

22nd Sep 2006, 6:40 pm	#24
harrybeadlebaum Retired Dormant Member Join Date: Feb 2006 Location: West Sussex, UK. Posts: 43	Re: marconi 2022e problem Hi Jazzy, On the subject of ESR, have you seen this old thread?: https://www.vintage-radio.net/forum/...&highlight=esr If you've not already seen it, have a look at Jim's "scope method" for checking the ESR of capacitors Regards, Harry.

22nd Sep 2006, 10:17 pm	#25
jazzy Retired Dormant Member Join Date: Aug 2006 Location: Essex, UK. Posts: 64	Re: marconi 2022e problem Hi mate I tried this method but to no joy, the way i connected it up was to place a BNC T piece on the output to my signal gen with one side of the T piece having a lead with croc clips on it (to test the caps) and the other side of the T piece having a lead going to another T piece what is connected to my scope with a 50 ohm load on the other side. I found this method on the internet to , I have the gen set to 100hz on square wave

26th Nov 2006, 12:25 am	#27
JoOngle Retired Dormant Member Join Date: Aug 2006 Location: Odense, Denmark Posts: 7	Re: marconi 2022e problem Interesting Thread! I've just purchased an Marconi 2022a myself and while it works just fine I might just look to change those old caps myself to "prevent" the wear and tear of the powersupply with such caps. It was exactly the same problem with my HP 8590a Spectrum Analyzer, blown 6.8 uF caps all over the Analog Interface shorting the -15v, after replacing (all) of those with fresh 10uF's - problem gone - works like a dream and have done so for a good while. Hm.. wonder if the 2022a and 2022e are somewhat identical, same design...same display....same buttons...hmm.

5th Jul 2007, 6:19 pm	#28
johngul Retired Dormant Member Join Date: Jul 2007 Location: Foothill Ranch, CA, USA Posts: 1	Re: marconi 2022e problem I have a 2022A that i'm trying to repair. The previous owner has messed around with IC15 and the matched schottky diodes on the lowest board (AB1)in an attempt to repair the output level (which is incorrect). I have the 2022A manual but it is missing chapter 5 (maintenance). I found the 2022E manual in PDF format but am suspecting that the AB1/2 board is different on the two 2022's. Can anyone confirm this? Specifically, i'm getting wrong voltages around IC15 when switching between 62 and 63 MHz (positive voltage is negative and vice versa when going over the 62.5 MHz limit).