Re: Francophones

Cursitor Doom <cd@notformail.com> 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.

Just to reinforce the point that Jeroen made, the adjustments interact,
so you will have to hop back and forth until the error becomes
negligible.  As far as I know. nobody has ever found a way around this
and it takes up a lot of time at the end of a production line.

A piece of equipment, which was a great help when I had that unenviable
job, was a signal generator with push buttons to rapidly and reliably
switch between the end-of-band spot frequencies.  I still had to wind
the dial drive from one end to the other each time - the reduction ratio
was 110:1.  (See <https://eddystoneusergroup.org.uk/Data Sheets/EC10 Oct
1967.pdf>.)

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk