Ekco U354 - UK Vintage Radio Repair and Restoration Discussion Forum

grindrod · 15th Apr 2005, 11:30 am

I bought the U354 as I wanted a nice VHF set for the workshop and I could't stand the thought of visiting Dixons to buy a cheap Chinese product with an established UK Brand name!!

The overall condition of the set was excellent with some restoration already done, I had bought it as 'for restoration' so I was pleasantly suprised, the half dozen or so axial Hunt caps had been replaced and everything else looked good and safe although the HT reservoir was bulging a bit.

I checked for shorts and then powered it up using Variac and isolation transformer, it took ages to warm up but eventually came to life with only 150 Volts of HT and dull looking valves.

I replaced the HT reservoir and powered it up with an Avo in series with the heaters, the current crept up to 75mA, I tuned the set to a local station and found that as the audio faded away the heater current sank to 40mA!!

At this point a cup of tea was called for and a good look at the circuit diagram, the only component common to HT and heaters was the dropper, a careful check revealed that the wiring had been replaced and was incorrectly wired so that the feed to the HT rectifier was made through part of the heater resistor, so as the HT current went up the heater current went down!!

A quick rewire and I had 100mA heater current and 228 Volts of HT!!

The set was now lively but the discriminator was obviously misaligned, so out with the sig genny and a quick realignment of IFs and discriminator and the set now sounds beautiful!! Sensitivity and frequency accuracy was good so I didn't attempt to realign the front end.

I can't help thinking that the poor chap who did the previous restoration was very unlucky not to have spotted his mistake!! It must have been very disappointing and frustrating to have done such a good job and then been foiled by a simple wiring error!

The audio quality is magnificent, much better than my wife's expensive Panasonic so the U354 has been uplifted from the workshop to reside in the dining room!!

Now that's what I call a good result!!

Cheers, Martin

Nickthedentist · 15th Apr 2005, 1:30 pm

That's a happy ending! And nice to see that the Ekco has got pride of place in the dining room

That wiring error reminds me of a Hacker Mayflower 2 I resored last year. When I got it, it worked, but the sound was faint and sensitivity poor.

I spent a weekend replacing loads of dodgy caps and resistors then switched on... exactly the same, even when I'd put in a fresh set of valves

After I'd done a few voltage checks, I found that I'd soldered one end of a resistor to the wrong tag on one of the long tagstrips. I put that right and... perfection at last

Nick.

15th Apr 2005, 11:30 am	#1
grindrod Retired Dormant Member Join Date: Feb 2005 Location: Stroud, Gloucestershire, UK. Posts: 57	Ekco U354 I bought the U354 as I wanted a nice VHF set for the workshop and I could't stand the thought of visiting Dixons to buy a cheap Chinese product with an established UK Brand name!! The overall condition of the set was excellent with some restoration already done, I had bought it as 'for restoration' so I was pleasantly suprised, the half dozen or so axial Hunt caps had been replaced and everything else looked good and safe although the HT reservoir was bulging a bit. I checked for shorts and then powered it up using Variac and isolation transformer, it took ages to warm up but eventually came to life with only 150 Volts of HT and dull looking valves. I replaced the HT reservoir and powered it up with an Avo in series with the heaters, the current crept up to 75mA, I tuned the set to a local station and found that as the audio faded away the heater current sank to 40mA!! At this point a cup of tea was called for and a good look at the circuit diagram, the only component common to HT and heaters was the dropper, a careful check revealed that the wiring had been replaced and was incorrectly wired so that the feed to the HT rectifier was made through part of the heater resistor, so as the HT current went up the heater current went down!! A quick rewire and I had 100mA heater current and 228 Volts of HT!! The set was now lively but the discriminator was obviously misaligned, so out with the sig genny and a quick realignment of IFs and discriminator and the set now sounds beautiful!! Sensitivity and frequency accuracy was good so I didn't attempt to realign the front end. I can't help thinking that the poor chap who did the previous restoration was very unlucky not to have spotted his mistake!! It must have been very disappointing and frustrating to have done such a good job and then been foiled by a simple wiring error! The audio quality is magnificent, much better than my wife's expensive Panasonic so the U354 has been uplifted from the workshop to reside in the dining room!! Now that's what I call a good result!! Cheers, Martin

15th Apr 2005, 1:30 pm	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 18,219	Re: Ekco U354 That's a happy ending! And nice to see that the Ekco has got pride of place in the dining room That wiring error reminds me of a Hacker Mayflower 2 I resored last year. When I got it, it worked, but the sound was faint and sensitivity poor. I spent a weekend replacing loads of dodgy caps and resistors then switched on... exactly the same, even when I'd put in a fresh set of valves After I'd done a few voltage checks, I found that I'd soldered one end of a resistor to the wrong tag on one of the long tagstrips. I put that right and... perfection at last Nick.