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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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16th Feb 2018, 10:52 am | #1 |
Rest in Peace
Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 7,306
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Telefunken Jubilate 1261
Recently I had occasion to carry out a minor repair to one of the above valve radios which I had extensively repaired about 9 years ago ,after the mains and o/p transformers had failed due to a faulty selenium rectifier, almost certainly s/c. and bad capacitors. At that time I replaced both transformers with similar Grundig types supplied by a fellow form member, but I don't recall posting pictures of my work on this forum back then. Apart from a couple of minor faults over the years, the radio has worked well ever since ( It is no longer in my possession, btw),but I'd be interested to read other members opinions of my handiwork. Perhaps I should have posted this in 'Success Stories', but after almost a decade I wondered if this section was more appropriate! (Mods. Please move if felt appropriate!)
N.B. There were meant to be pictures accompanying this post, but, unfortunately I cannot find them (oops!!) Apologies for the omission. Last edited by 'LIVEWIRE?'; 16th Feb 2018 at 11:13 am. |
16th Feb 2018, 12:47 pm | #2 |
Rest in Peace
Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 7,306
|
Re: Telefunken Jubilate 1261
Further to the above I've now found one picture I took after repairing/refurbishing the Jubilate, plus my (hopefully readable) notes concerning the Grundig Mains and o/p Transformers used to replace the faulty (burned out) original Telefunken ones.
In case my handwritten notes are illegible, they read as follows; I wired the mains transformer so that F1 (4Amp)(S13) is the heater line fuse, F2(S12) (63mAT)is the HT Line fuse, whilst F3(S11)(200mA) is the mains fuse. This is to agree with the legends on the radio rear cover. I also replaced the original two-core mains lead with a 3-core 3Amp rated mains lead, with the earth connection taken to a tag located under the chassis close to the reservoir/smoothing capacitor. Since a D.P. mains switch was fitted by Telefunken, who only used one pole, I wired the new mains lead so that both L & N are switched. The original selenium rectifier was replaced with a silicon bridge one made up with 4x 1n4007 with a 390 ohm 2 watt series resistor in series with the DC (HT) line,wired between the rectifier positive and the reservoir capacitor (sketch on this page). Apart from a couple of minor faults, the radio has worked perfectly for 8/5 years since my repair. Regardimng the o/p transformer, unlike the original, the replacement Grundig one has no hum cancelling tap. Despite this only a very small amount of hum is auible, and that only at high volume settings with no signal present. I don't know how many dB down compared to an input signal this is as I didn't record such data! Last edited by 'LIVEWIRE?'; 16th Feb 2018 at 1:08 pm. Reason: To clarify my handwritten notes |