Barker 88 Intermediate
 

Hi folks,
I've completed restoration of a Barker 88 Intermediate version, apart from the cabinet. The main problem was that the Lectrona audio output transformer had one side of the primary o/c so only one of the 6V6 output valves was doing all the work. I got the transformer out (it was riveted to the speaker frame) and once again Ed Dinning came to the rescue :thumbsup: with a rewind (another case of green spot rotting the windings). Apart from replacement of a few capacitors the rest was reasonably straightforward. The main HT smoothing can reformed satisfactorily and the 2 grid coupling capacitors on the output valves were faultless. The 6Q7GT detector/pre-amp anode load resistor (240k) was o/c and replaced with a 250k. This happens quite often, not sure why because these triodes have very low anode current. The 6K8GT frequency changer was low emission so I replaced it. The 6V6GT output valves weren't well matched but I matched one of them with a 6V6G from the spares box. The 6U5G magic eye had gone blind so I replaced it with a decent one from spares. On powering up, the HT was too high maybe because a previous owner had fitted a GZ30 indirectly heated rectifier. I managed to drop about 20v HT by substituting a directly heated U50. The set worked on all bands but was a bit deaf. I realigned it successfully and sensitivity was much improved. The circuit is different from Trader #747. It most closely matches the circuit in the Radio museum website. The alignment instructions in the Trader Sheet needed modifying as did the identification of the coils and trimmers adjustment sequence. I have updated the procedure and attached it to maybe save somebody else the trouble. If anybody spots errors let me know and I'll amend it. Otherwise I'm happy for Paul to include it in the library/on CD if suitable. It's a nice sounding set and works well even though it is a fairly bog standard superhet without RF amplifier. Cheers, Jerry

Re: Barker 88 Intermediate
 

Nice job Jerry. These sets seem to be in demand lately, judging by recent sale prices on popular auction sites.

Any chance of some pictures?

Gabriel

Re: Barker 88 Intermediate
 

Re prices, are you referring to a certain new and boxed one I wonder without drifting too far OT ?

Re: Barker 88 Intermediate
 

No, this was the one from the online BVWS auction. Not pristine but still very nice example (even better now that it works) :) . Pics attached, inc 2 images of the speaker transformer prior to rewind. I protected the cone and simply drilled out the rivet heads to remove it. I was then able to fit self tappers into the holes left in the frame casting to refit the transformer after rewind. Cheers, Jerry

Re: Barker 88 Intermediate
 

Thank you Jerry.

Re: Barker 88 Intermediate
 

Looks great jerry