11-11-2017, 09:21 PM
(This post was last modified: 11-11-2017, 09:27 PM by Old Sparky.)
Reading both your posts, Trevor, and dealing with points as they arise. I was powering the radio from a variable voltage mains PSU (actually an ex-Blaupunkt demonstration stand supply, which, more than 20 years ago now, Ibuilt into a metal case, fitted a Voltmeter, and panel mounted voltage control, which allows any voltage fron virtually zero to 17vDC to be applied to whatever is being powered, The PSU can deliver up to 10 Amps, and is a conventional linear supply using 2N3055 transistors. As to the other points you make, first I have to replace the reservoir/smoothing cap. I removed the new one I'd fitted several years ago to use in a record oplayer, and have yet to fit a replacement. I replaced all thhe original caps, plus various other out of spec. components, and fitted a modern electronic 'vibrator' in place of the original mechanical one. What I haven't yet done, but will do when next i get the Frankfurt on the bench, is to bond the head unit and power pack together with braid, and run the radio with the covers on. I had also replaced the original selenium rectifier with 4 x 1N4007 diodes with a series resistor. IIRC the reservoir & smoothing caps were originally 32 + 16 uf, but the new one was 2 x 32uf. I won't take up your offer of Aircraft quality screened lead at the moment, but may well do so at a later date, maybe in the New Year. In the meantime thanks for your comments and suggestions, which should help me to solve the problem(s)
Re-reading some of the earlier posts, and in particular Mark's comments about it being a complex set, I'm sure there was an even more complex one, called the Koln, which had Motorised self-seek tuning.
Re-reading some of the earlier posts, and in particular Mark's comments about it being a complex set, I'm sure there was an even more complex one, called the Koln, which had Motorised self-seek tuning.
