XPost: sci.electronics.design
From: cd@notformail.com
On Sat, 21 Dec 2024 21:31:51 +0100, Jeroen Belleman
wrote:
>On 12/21/24 14:57, Cursitor Doom wrote:
>> On Sat, 21 Dec 2024 08:57:51 +0000, liz@poppyrecords.invalid.invalid
>> (Liz Tuddenham) wrote:
>>
>>> Cursitor Doom wrote:
>>>
>>>> On Sat, 21 Dec 2024 00:05:08 +0100, Jeroen Belleman
>>>> wrote:
>>>>
>>>>> On 12/20/24 22:16, Cursitor Doom wrote:
>>>>>> On Fri, 20 Dec 2024 19:32:14 +0000, liz@poppyrecords.invalid.invalid
>>>>>> (Liz Tuddenham) wrote:
>>>>>>
>>>>>>> Cursitor Doom wrote:
>>>>>>>
>>>>>>>> Do we have any French speakers on the Panel? I have a radio that's
>>>>>>>> badly in need of realignment and the only instructions I can find are
>>>>>>>> a set in French. I can't use Google translate because they've used too
>>>>>>>> many abbreviations in the text and they won't parse any sense.
>>>>>>>
>>>>>>> I'm not a particularly fluent French speaker, but I could probably sort
>>>>>>> out some technical instructions in French If you want to send them to
>>>>>>> me, I'll have a go (you should be able to work out my e-mail address).
>>>>>>
>>>>>> Many thanks indeed for your kind offer. I suspect it will probably
>>>>>> require a native French speaker to decypher, but who knows? :-)
>>>>>
>>>>> I'm not a native French speaker, but I may be able to help anyway.
>>>>> Fire away.
>>>>
>>>> Well that's interesing as I had did think you might respond given some
>>>> of the background you've revealed here in the past. I don't have the
>>>> relevant page here right now, but will make it available tomorrow. It
>>>> is only the one page and only one column of that, so nothing too
>>>> onerous. I did show it to a genuine French chum of mine a few weeks
>>>> ago, but he was stumped by the technical side of it and couldn't
>>>> assist much, unfortunately. So it appears it needs someone who can
>>>> speak French fluently *and* understands the process of radio
>>>> alignment. I kind of guessed that might be you....
>>>
>>>
>>> Many years ago Practical Wireless published an article about the French
>>> 819-line high-definition television service which had been translated
>>>from French by someone who knew nothing about television or radio
>>> terminologyy. It was hilarious nonsense but I eventually managed to
>>> translate it back into French so that I could understand it.
>>>
>>> If you post your text here, we can all have a go at it.
>>
>> Sorry for the delay; took a bit of tracking down but I have it now:
>>
>> https://disk.yandex.com/i/3SiZ6rN_k-fP4w
>>
>> It's only page 1 that needs the translation - and of that, in
>> particular the abbreviated bits. I haven't read French since I was in
>> school about a hundred years ago, so it's all Dutch to me. :-)
>
>
>This was translated from German into French by someone who also
>did not know clearly what it all meant. Not everything makes
>perfect sense.
>
>Also, while it doesn't say so, many of the adjustments interact,
>so you may have to go back and forth a few times. Anyway, here
>goes.
>
>Jeroen Belleman
>
>
>===============================================================
>
>-- DC current adjustments (for 9V supply)
> - Adjustment of the push-pull audio stage:
> Cut the solder bridge marked -x- in the collector trace of the
> AC188 T11 and insert a current meter. Adjust R410 for 6.5mA.
> Restore the bridge.
> - Adjustment of the IF amplifier:
> Set R515 to obtain 1.35V across T4's emitter resistor R518.
>
>-- Adjustment of the FM-IF stages. The radio should be set to "FM".
> Connect a wobbulator centered on 10.7MHz at MP5 and the diode
> detector shown at ZF VII (I think...) MP6. Detune ZF VIII (a).
> Then tune ZFVII (b) for a symmetrical maximum response.
> - Inject signal at MP3 and tune ZF VI (c) and ZF V (d) for
> symmetrical maximum response.
> - Inject signal on MP2 and adjust ZF IV (e) and ZF III (f) for
> symmetrical maximum response.
> - Inject a weakly coupled signal at the mixer (MP1?) and adjust
> ZF II (g) and ZF I (h) for symmetrical maximum response.
> - Discriminator: Inject signal at MP5, with a level low
> enough that no limiting occurs in the IF strip. Observe the
> signal at MP11 (audio amplifier input) with load impedance 50k.
> Adjust ZF VIII (a) for symmetrical response.
>
>-- Adjustment of the AM IF (460kHz) stages. The radio should be
> set to "PO" (AM, 560-1450kHz). Connect a measurement instrument
> at MP4 (Weakly coupled).
> - Inject a wobbulator signal at MP3 and adjust ZF XIII and ZF XII
> for symmetrical maximum response.
> - Inject signal at MP8 and adjust ZF XI for symmetrical maximum
> response.
> - Inject signal at MP7 and adjust ZF X and ZF IX for symmetrical
> maximum response.
>
>-- Adjustment of local oscillator and AM input. For short and
> medium wave, couple signal into the ferrite rod antenna using
> the frame. For short wave, remove the rod antenna and couple
> signal at the antenna connection through 15pF.
> Tune to 560kHz and adjust (1) and (3) for maximum response.
> Mixer sensitivity 13uV and oscillator output 60-90mV.
> Tune to 1450 kHz and adjust (2) and (4) for maximum response.
> - Set the radio to GO (Long wave, 160-240kHz).
> Tune to 160kHz and adjust (5) and (6) for maximum response.
> Mixer sensitivity 13uV and oscillator output 65-95mV.
> - Set the radio to OC (Short wave, 6.5-15MHz)
> Tune to 6.5MHz and adjust (8) and (10) for maximum response.
> Tune to 15MHz and adjust (9) and (11) for maximum response.
> Mixer sensitivity 5uV and oscillator output 35-90mV.
>
>-- Adjustment of the FM LO. Signal from an RF generator with
> 60 Ohm output impedance injected directly at the mixer (MP1?)
> with a loaded signal level <2mV. Set the radio to FM.
> - Tune to 88MHz and adjust (A) and (C) for maximum response.
> - Tune to 106MHz and adjust (B) and (D) for maximum response,
> Noise level is about 5 times kT0. Oscillator output voltage
> 75-85mV (at T2's emitter).
Thanks, Jeroen. Geez, you just can't win with these bastards. I've got
a 50 ohm signal generator and a 70 ohm one - but that's not good
enough for 'em. No, they want me to splash out on a 60 ohm one and
where am I going to source one of those??
And it doesn't stop there! I thought all my vintage servicing voltage
reading requirements would be met when I bought an old analogue Avo
with 20kohms/volt. But now it seems I need to scratch around for a
500ohms/volt one. It seems they're expecting whoever services these
[continued in next message]
--- SoupGate-DOS v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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