>? How many peak volts on your 'scope? With "normal" ALC indication, my
>TS-440S overshoots to about 120v-p. into 50-ohms. .
>
>I didn't measure it on my scope because I thought I needed a fast
>peak-reading or storage scope.
? A triggered scope with a vert.-deflection delay line will see the
leading edge.
> I have a peak-reading RF DVM now, but I think
>the minimum pulse width is 1ms. One of these days I'll see if my HP scope is
>fast enough to show it in the phosphor persistence.
>
>The test procedure you describe in a other post implies that you've tested
>the 440 only for SSB overshoot. Try it with CW.
? I did. Running it in the ALC ok zone makes for a fast rise time.
>
> While a sharp syllable might
>have a pretty fast rise time, I would bet that the CW waveform rises much
>faster, exacerbating the problem of slow rise time on the ALC. Also, QSK CW
>is likely to cause a stream of spikes, whereas SSB will probably cause
>spikes mostly when the VOX is initially tripped.
? I set my VOX fast to enough to drop at commas and periods because I
want to hear comments. I do not remain in a conversation with anyone
who does not let the VOX drop at the end of sentences.
>I found this to be true
>under contest battle conditions -- the 87A tripped much more often in CW
>contests than SSB contests. I'm sure when it did trip in SSB contests I was
>frantically bleating my call.
>
? 3cx800a7s can be driven to full output with a lot less drive than is
typically available. One workaround is to add 50 ohms in series with
each cathode of a pair. This raises the driving Z from c.25-ohms to
c.50-ohms - and it makes the cathodes virtually impossible to overdrive
with typical transcievers. An added benefit is that the cathode feedback
resistors automatically balance the anode currents in unmatched tubes. .
.
>.......
>Well, another reason I replaced the 950 with a 1000mp is that the 950
>overloaded with strong adjacent signals during contests. I'm not sure that's
>exclusively an AGC problem,
? probably not. It sounds like a vco noise problem.
>but I'm sure it's involved. I've always thought
>the IF filters on the 940 and 950 are not very good
? the measured shape factors are quite good.
>......
- cheers, Dick
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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