Ekco U353 Basket Case repaired!

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There is a beautiful chap at work referred to as Terry, who likes to revive previous radios and report gamers. He arrived with this previous Ecko U353 in bits in a field. “It is obtained minimize wires and labels and has been obtained at. Would you prefer it?” Why not …

Electronic Repairing

Electronic Repairing

 Wires minimize. Appears to be like like somebody was going to vary the mains smoothing capacitor.

Electronic Repairing

 UL84 getter seems unhealthy.

Electronic Repairing

Many of the white lettering from the dimensions has gone…

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… however on the entire the chassis seems affordable.

Electronic Repairing   The mains smoothing cap will not be authentic, has been disconnected and is dated Feb ’65. It has poor ESR….

Electronic Repairing   .. so every of it is three sections is given just a few hours on the ole’ MK87 Dreadnaught capacitor reformer…..

Electronic Repairing
 …. in the meantime the unhappy wanting UL84 is examined on the AVO two-panel valve tester…

Electronic Repairing

Electronic Repairing

A tragic 1.5 mA per Volt. Minimal for a brand new valve is 9 mA per Volt. No good in any respect….

Electronic Repairing

Fortunately, we’ve a NOS substitute. Simply have a look at the distinction within the gettering (that is the shiny bit on the high). The brand new valve is on the left. The gettering is brilliant and has a pleasant sharp edge. The blacker the gettering is, the higher. This new valve reads 15mA per Volt on the AVO!

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Stamped on the chassis is a date … 1st Sept …19 ?? 1957 maybe? Appears a bit early for this receiver…

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There have been many leaking and cracked Hunts capacitors to be modified, together with some suspect TCC electrolytics. The cathode bypass capacitor for the UL84 was short-circuit. That is most likely why the valve was worn out.

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 Remembering how there was a small decoupling capacitor within the U319 VHF tuner, which induced points, I eliminated the quilt to this unit (a a lot simpler job that the U319!!!)

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However the decoupling caps are Ireland sorts, and all learn in excellent situation…

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So, after leaving the mains smoother on the reformer with all three sections in parallel, the leakage had dropped to a really low 50uA!  ESR was good too, so it was re-installed and linked up. So all in all, 1 valve and 9 capacitors, and we’re able to go! Connect with the protection mains isolation transformer, swap on ….

Electronic Repairing   … and after a couple of minutes heat up time, the DM70 indicator tube lights, and the set performs effectively…

Electronic Repairing

In widespread with most mains units of the interval, the metallic chassis is linked straight to 1 facet of our AC line (in regular observe, the impartial)… that is known as a “reside chassis” (even whether it is impartial) , which imply the shafts for the controls are additionally “reside”. Now, till a set of insulating knobs could be discovered, this set can solely be safely operated although an isolation transformer.

Electronic Repairing

I did find a pleasant shiny set of plastic knobs at a supplier regionally. While the knobs are plastic, the shiny coating have to be metallic, as they conduct very effectively! These will NOT be protected!

Anyhow, here is some handsome chap to elucidate the set to you!

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