[Drake] Drake's Welcome Too!

[Tony Sokol]

Hi Michael,

  Two of the most common mistakes made running older equipment is that of having the
mike gain turned way up causing severe clipping and / or flat topping resulting in
really bad audio.  That is the first thing to check.  You want to run the gain only
high enough to see some ALC action and that's it.  (I have an mint Hallicrafters
SR-400A that is real easy to overdrive and when I do, it sounds bad!)  Some people
that do not understand SSB transmission are unaware of mechanical meter dynamics and
try and get the watt meter to show full output.  It doesn't work that way.  Also you
need to make sure the rig is tuned up properly with maximum grid drive and a
properly dipped final.
    The next most common thing that happens is that someone will try and tune up the
rig into a really crummy antenna and have all kinds of RF getting back into the
rig's audio causing sever distortion.  A good well matched antenna and ground is
essential here.  Did your "good audio" reports come on the same band or did you
change bands.  You can get RF feedback on some bands and not on others.
    Other problems include a mike impedance mismatch or the use of an amplified
mike.  Many who have their roots in CB are prone to think that the more audio, the
better.  Absolutely not true, in fact, in most cases the opposite is true.  Most
audio amplifiers and compressors sound the best in the "off" position.  Another
possibility is that of an intermittent ground or shield connection on the microphone
itself.
    I wasn't there but "changing all capacitors" doesn't sound like a knowledgeable
first response.  True, a lot of the older large paper caps and silver micas go bad
causing problems but the problem is usually permanent until the culprit is found.  I
would only change them all if I were doing a complete restoration including retubing
(only the weak ones) and alignment.  You need to make sure that all of the earlier
mentioned problems areas are dealt with first.  It could also be a bad tube.  Some
tubes like the 6U8A are famous for grid to cathode shorts causing bad audio problems
in Collins gear for instance.
    Lastly, whenever you check into a group of true hams such as those found in the
various "vintage" groups, they will tell you if you signal is bad and that is a good
thing.  I want to know that I have a problem and fix it.  I can't believe how many
times I hear someone that has lousy sounding distorted but strong signal and someone
tells him, "Great signal here, 40 over 9, what did you say your name was?"  "Missed
you QTH too."  It doesn't have anything to do with age or experience either.  We
have a lot of younger as well as older new hams who get a lot of self-satisfaction
from rebuilding the older vintage equipment and making it sound even better than the
latest $4,000 dollar Kenyaecom.  Weather it is vintage tube or modern solid state
equipment, most of us strive to have a nice strong clean signal that we can be proud
of.  If we have a problem, we want someone to be honest and tell is about it so we
can deal with it right away.
    Them's my .02  cents worth.  :-)  Good luck.


Tony - W9JXN
Michael Smith wrote:

> I would advise that if you check in with a Drake that it be in perfect working
> order. Apparently I had less than perfect audio on my TR3 when I checked in and
> was told to go change  *ALL*  of the capacitors in the rig and then come back.
> After that I was ignored. Audio checks that evening with other stations were
> fine. There must have been an intermittent somewhere..... or something just
> didn't clique?
>
> Michael
> N�XY
>
> >Park that snowmobile, ground the surf board, hang up the ice skates and put the
> >Jet Ski in dry dock. Power up the Hallicrafters, or other boat anchor, and join
> >us for the Sunday January 20th Hallicrafters Collectors International 20 meter
> >Net.
>
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