Ekco T161 with disappearing EHT - CRT? - UK Vintage Radio Repair and Restoration Discussion Forum

brianc · 17th Mar 2006, 9:20 pm

Hi all
I'm working on a T161. After the normal capacitor changes I ran it up slowly on a variac and checked that the timebases were working. They looked OK after a valve change and I even got 9kV EHT (without the tube connected). However, connecting the EHT cable to the tube's final anode, the EHT dropped to about 1.5kV and a "singing" noise came from the tube! It sounded as though there was arcing inside the tube but I couldn't see anything. Can anyone suggest what's happening? Can it be that the tube is duff?
(I took the tube out of its cradle so that there was no nearby chassis potential but the coils were on the neck and the base was connected.)
Strange!!!

Cheers

Brian

Danny · 17th Mar 2006, 11:23 pm

Sorry to be the person to answer this but the tube is soft and has air in it
the strange noises are common when this happens its the sparks jumping around inside .
Danny
Ps you have disconnected the visconol cap! (just a hope that you havent)

Heatercathodeshort · 18th Mar 2006, 1:17 pm

Hello Brian,
What a pity, another rare crt lost for ever. The CRM121 series are very hard to find in any sort of reasonable condition. Television sets just cannot be simply 'posted'. Just last night I did an overnight parcel trunk run to a very large company just off the M5. [ Not the R.M.] The parcels get thrown around a great deal and get mixed with things like car gearboxes. Its like a massive crushing machine. You would need a wooden crate with around 12" of space all round to guarantee some sort of success, and this in turn strapped to a pallet so that it can be handled with a fork lift. I can only suggest to forum members, to avoid this heartbreak that is all too common, you personally collect the items concerned. Other members may be able to collect items and store them until it is convenient for them to be collected.This is the only way to stop the damage. There have been many threads on this matter recently. Very sorry again. John.

Danny · 18th Mar 2006, 11:29 pm

Hi it took me testing seven tubes to find a good one so i wouldnt hold much hope but sets in poor condition do turn up with usable tubes so i recon thats what you must hope turns up but then others will also be looking for spare crts!. i know it seems cheaper to have things posted but
teles just dont seem to survive parcel carriers . happy hunting and hope you find one soon. Danny

17th Mar 2006, 9:20 pm	#1
brianc Rest in Peace Join Date: Jun 2004 Location: Burghfield, Reading, Berkshire, UK, Posts: 1,055	Ekco T161 with disappearing EHT - CRT? Hi all I'm working on a T161. After the normal capacitor changes I ran it up slowly on a variac and checked that the timebases were working. They looked OK after a valve change and I even got 9kV EHT (without the tube connected). However, connecting the EHT cable to the tube's final anode, the EHT dropped to about 1.5kV and a "singing" noise came from the tube! It sounded as though there was arcing inside the tube but I couldn't see anything. Can anyone suggest what's happening? Can it be that the tube is duff? (I took the tube out of its cradle so that there was no nearby chassis potential but the coils were on the neck and the base was connected.) Strange!!! Cheers Brian

17th Mar 2006, 11:23 pm	#2
Danny Heptode Join Date: Jul 2003 Location: North Walsham, Norfolk, UK. Posts: 516	Re: Ekco T161 with disappearing EHT Sorry to be the person to answer this but the tube is soft and has air in it the strange noises are common when this happens its the sparks jumping around inside . Danny Ps you have disconnected the visconol cap! (just a hope that you havent)

18th Mar 2006, 1:17 pm	#3
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Ekco T161 with disappearing EHT Hello Brian, What a pity, another rare crt lost for ever. The CRM121 series are very hard to find in any sort of reasonable condition. Television sets just cannot be simply 'posted'. Just last night I did an overnight parcel trunk run to a very large company just off the M5. [ Not the R.M.] The parcels get thrown around a great deal and get mixed with things like car gearboxes. Its like a massive crushing machine. You would need a wooden crate with around 12" of space all round to guarantee some sort of success, and this in turn strapped to a pallet so that it can be handled with a fork lift. I can only suggest to forum members, to avoid this heartbreak that is all too common, you personally collect the items concerned. Other members may be able to collect items and store them until it is convenient for them to be collected.This is the only way to stop the damage. There have been many threads on this matter recently. Very sorry again. John.

18th Mar 2006, 11:29 pm	#4
Danny Heptode Join Date: Jul 2003 Location: North Walsham, Norfolk, UK. Posts: 516	Re: Ekco T161 with disappearing EHT Hi it took me testing seven tubes to find a good one so i wouldnt hold much hope but sets in poor condition do turn up with usable tubes so i recon thats what you must hope turns up but then others will also be looking for spare crts!. i know it seems cheaper to have things posted but teles just dont seem to survive parcel carriers . happy hunting and hope you find one soon. Danny