Arnold Ziffel <a...@h...invalid> wrote:

> Przeklejam swojego posta z grupy dyskusyjnej transceivera QDX. Może wy coś
> podpowiecie...?

Aktualizacja:

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I've read the topic called "QDX IC7 Voltages".

It's not a lock-up in my case. Slowly rising power (starting with 1.5 V)
didn't fix it, nor did shorting C71...74 or doing the factory reset. And
I'm running firmware 1_05 by the way.

Now the most interesting part.

During audio sweeps, the problem disappears on 40m and 60m bands. The
sweeps still look bad (on 40m USB is at -31 dB, on 60m at -33 dB), but the
voltages appear.

It's correlated with the BPF number. Proper voltages appear for bands with
the BPF number 1 (when I switched 20m to BPF number 1, voltages appeared).

Voltages at the input of C71...74 also differ during these tests. With BPF
1 selected, C71 receives 3.69 V from IC4. With other BPFs, it receives
0.349 V. It shouldn't have anything to do with IC7, unless there's a small
AC voltage there, but I can't measure any (after the sweeps complete), at
least with my equipment.

I measured BPF capacitors to ground. C30 and C28 have around 3.15 Mohm,
C31 and C29 have infinity (too large resistance for me to measure).

I measured the continuity of the BPF inductor -- it's OK for all taps.

The more I dig into it, the less I understand what's going on...
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--
Słonica namawia mrówkę, by ta jej weszła do... Po dłuższym nagabywaniu
mrówka wchodzi i wychodzi trąbą. Słonica rozanielona prosi o powtórkę
i wreszcie mrówka się zgadza. Wchodzi, a słonica wkłada sobie trąbę i
myśli :
"Ach, wieczna rozkosz!"