EKCO U245 reservoir cap and smoothing cap ! - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

benjamin77 · 18th May 2009, 2:22 pm

Just checked that the plug is wired correctly and it is, switched on and took a reading from the out put and the chassis on one side of R19 yellow,violet,brown and it gave 114V on the other side 113v nearest the cap.

Also when I touched the deck with the - probe it gave interfierance through the speaker. Left it running on full mains voltage and turrned the tuning control and it crackled faintly tuning in to a station.....!

Station X · 18th May 2009, 2:39 pm

As you refer to R19 I'll assume you're using the Trader Sheet.

You have low HT voltage. It should be nearer to 170V DC. (Without the test lamp).

Make sure you have the correct voltage selected.

Use your meter on ohms range to check R19, 20, 21 and 22.

Power up without the lamp limiter and measure the AC voltage on V5 anode. It should be 205V AC.

If all in order low HT indicates a faulty rectifier or that the set is drawing excess HT current. In the latter case I'd say C26 is a likely culprit. Disconnect the positive end and see if the HT rises. If so replace C26.

You need to check DC voltages on all the valves. This should quickly show up any faults.

Steve_P · 18th May 2009, 2:41 pm

Well if the smoothing caps are OK, try C26 (Trader) or C18 (Ekco sheet.) Also try C31 (Trader) or C19 (Ekco sheet.)

What happens if you lift the first grid of the pentode. (UL41).

Cheers,

Steve P.

benjamin77 · 18th May 2009, 4:57 pm

Results are :-

R19 543
R20 174
R21 980
R22 212

When I re capped the chassis I changed :-
c26
c31
as well as a al the others that had spewed there waxy guts all over the place..

I guess the next thing would be to test the voltage on V5 anode but some guidance on this one please...

Steve_P · 18th May 2009, 5:27 pm

Well the anode is probably OK, but switch to AC and go between Pin 7 of the rectifier and the neutral side of the On-Off switch.

It's either the rectifier valve, the caps you put in or something we have all missed.

Cheers,

Steve P.

benjamin77 · 18th May 2009, 6:33 pm

ok took some readings from V5 pin 7 (red wire going to + side of c32) it reads 135v .

So I would take a guess with my limited knowlefge that the valve i the problem ?

Station X · 18th May 2009, 6:51 pm

Pin 7 is the rectifier cathode. The voltage at this point is DC. It does sound low, but as I said earlier something could be pulling the voltage down. Is it possible to remove the wires going to C33 positive (apart from that going to R19 and then check the DC voltage at that point?

yestertech · 19th May 2009, 7:02 pm

I have a UY41 on standby should you need it !

Andy

18th May 2009, 2:22 pm	#21
benjamin77 Retired Dormant Member Join Date: May 2009 Location: High Wycombe, Buckinghamshire, UK. Posts: 326	Re: EKCO U245 reservoir cap and smoothing cap ! Just checked that the plug is wired correctly and it is, switched on and took a reading from the out put and the chassis on one side of R19 yellow,violet,brown and it gave 114V on the other side 113v nearest the cap. Also when I touched the deck with the - probe it gave interfierance through the speaker. Left it running on full mains voltage and turrned the tuning control and it crackled faintly tuning in to a station.....!

18th May 2009, 2:39 pm	#22
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: EKCO U245 reservoir cap and smoothing cap ! As you refer to R19 I'll assume you're using the Trader Sheet. You have low HT voltage. It should be nearer to 170V DC. (Without the test lamp). Make sure you have the correct voltage selected. Use your meter on ohms range to check R19, 20, 21 and 22. Power up without the lamp limiter and measure the AC voltage on V5 anode. It should be 205V AC. If all in order low HT indicates a faulty rectifier or that the set is drawing excess HT current. In the latter case I'd say C26 is a likely culprit. Disconnect the positive end and see if the HT rises. If so replace C26. You need to check DC voltages on all the valves. This should quickly show up any faults. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

18th May 2009, 2:41 pm	#23
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: EKCO U245 reservoir cap and smoothing cap ! Well if the smoothing caps are OK, try C26 (Trader) or C18 (Ekco sheet.) Also try C31 (Trader) or C19 (Ekco sheet.) What happens if you lift the first grid of the pentode. (UL41). Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

18th May 2009, 4:57 pm	#24
benjamin77 Retired Dormant Member Join Date: May 2009 Location: High Wycombe, Buckinghamshire, UK. Posts: 326	Re: EKCO U245 reservoir cap and smoothing cap ! Results are :- R19 543 R20 174 R21 980 R22 212 When I re capped the chassis I changed :- c26 c31 as well as a al the others that had spewed there waxy guts all over the place.. I guess the next thing would be to test the voltage on V5 anode but some guidance on this one please...

18th May 2009, 5:27 pm	#25
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: EKCO U245 reservoir cap and smoothing cap ! Well the anode is probably OK, but switch to AC and go between Pin 7 of the rectifier and the neutral side of the On-Off switch. It's either the rectifier valve, the caps you put in or something we have all missed. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

18th May 2009, 6:33 pm	#26
benjamin77 Retired Dormant Member Join Date: May 2009 Location: High Wycombe, Buckinghamshire, UK. Posts: 326	Re: EKCO U245 reservoir cap and smoothing cap ! ok took some readings from V5 pin 7 (red wire going to + side of c32) it reads 135v . So I would take a guess with my limited knowlefge that the valve i the problem ?

18th May 2009, 6:51 pm	#27
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: EKCO U245 reservoir cap and smoothing cap ! Pin 7 is the rectifier cathode. The voltage at this point is DC. It does sound low, but as I said earlier something could be pulling the voltage down. Is it possible to remove the wires going to C33 positive (apart from that going to R19 and then check the DC voltage at that point? __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

19th May 2009, 7:02 pm	#28
yestertech Nonode Join Date: Dec 2002 Location: Coulsdon, Surrey, UK. Posts: 2,135	Re: EKCO U245 reservoir cap and smoothing cap ! I have a UY41 on standby should you need it ! Andy