On Sun, 22 Dec 2024 15:52:08 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:

>On 12/22/24 14:27, Cursitor Doom wrote:
>> On Sun, 22 Dec 2024 12:37:37 +0000, liz@poppyrecords.invalid.invalid
>> (Liz Tuddenham) wrote:
>>
>>> Jeroen Belleman <jeroen@nospam.please> 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 <cd@notformail.com> wrote:
>>>>>>
>>>>>>> On Sat, 21 Dec 2024 00:05:08 +0100, Jeroen Belleman
>>>>>>> <jeroen@nospam.please> 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 <cd@notformail.com> 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).
>>>
>>> It is interesting to compare the different approaches Jeroen and I have
>>> taken. Although we began with exactly the same source material, we have
>>> produced two markedly different ways of saying the same thing.
>>
>> Well, the important thing is that you agree on the key points.
>> Now it just so happens I have a vintage wobbulator (made by Knight
>> IIRC) which would be ideal for this job. It hasn't been used for about
>> 20 years so it'll probably explode at switch-on, but that's nothing
>> unusual around here as my neighbours will attest.
>
>I went back and forth between the text and the schematics to
>try and clear up some inaccuracies in the text. Comparing with
>the original German text, the G->F translator did an honourable
>job, in fact.

But not with those all-important abbreviations!

>I believe you have a VNA. I'd use that instead of a wobbulator.
>You won't need the diode detector then. You'll need a high-Z
>probe though. You'll also need an oscilloscope to observe the
>audio amplifier input (to adjust the discriminator).
>
>Jeroen Belleman

Yes, I do have a couple of lab grade VNAs, but I really don't see how
they could be used to good effect in this situation? Surely a
wobbulator is king here? Attempting to use a VNA would just create
another set of obstacles AFAICS because I would really require a
fixture to get meaningful results and getting a fixture for this
specific transistor radio would mean building one, which is for me
right now totally impractical (not to mention massive overkill!)