Bit - really HARD!

Bob Maser w6tr at MINDSPRING.COM
Thu Oct 21 01:50:02 EDT 1999

Pardon me for butting in here on this subject but when I first became a
novice in 1956, I owned a Lysco transmitter but I don't remember the model
number.  It could have been a 600.  All I remember was that it had a fairly
large VFO and it was painted in a black wrinkle finish. It was strictly CW
but it did have an outboard modulator that I believe was homebrew.  Seems
that it ran a single 807 but I may be wrong.   It had a matching device
bolted on the left side of it.  Seems that it put out about 15-20 watts.  Do
you have any idea as to what model it was?  I have always wanted to find one
to add it to my collection.  I used it as WP4AIU in Mayaguez PR and worked
all states with it on 15 meters in less than 1 year.  I would appreciate any
info you might be able to provide

73 Bob  W6TR
-----Original Message-----
From: Perry Ballinger <w8au at SSSNET.COM>
Date: Wednesday, October 20, 1999 10:40 PM
Subject: Re: Bit - really HARD!

>Interesting problem you had there.   (And you thought you were playing it
>safe by not putting your hand behind the rig where the B+ feedthru
>insulators are!)
>Having had a few Lyscos over the years, and still having one, I am
>surprised someone would do such a bonehead modification!  Years ago, I
>learned something from to make a "grid-blocked" keying
>arrangement with NO grid bias supplies!  Just float the operating ground a
>few volts above chassis ground, enough to make the 807 cathode that much
>positive with respect to the grid so you get "cut-off."  The simplicity was
>fascinating!  Just tie the key jack across the last resistor in the bleeder
>circuit string to short out the "bias" voltage and it keys....  How neat!
>I then learned to tailor that last resistor to get a few mills static plate
>current, to ease the "turn-on" of the 807.   My, such neat memories!
>Think you will eliminate a sure key click when you get your's back to
>normal.  Hope to hear it sometime....
>Perry    w8au
>At 04:10 PM 10/20/99 -0400, you wrote:
>>     Two nights ago I put the Lysco 600 on the air.  Was doing
>>fine with it... but in the course of things the back of my hand
>>came across the key terminals and I got bit - HARD!  Over the
>>years I have got zapped, of course, but this really hit me.
>>     Next day, as soon as I finished repairing my VOM, I checked
>>the voltage across the key -- about 450 volts...  Certainly enough
>>to kill the unwary/unknowing.  I remembered what I had encountered
>>when inside the Lysco a few days earlier: there was a resistor
>>string that went to the key jack, with a final 1250 ohm resistor
>>across the jack.  The entire string had been replaced by a single
>>resistor - across the jack - correct TOTAL resistance so the rig
>>operated OK, but that put the full voltage on the key.
>>     So it looks like I WILL go back in and restore it to its
>>original configuration, just as a safety feature if nothing else.
>>I had noted what had been done in the change, but had not thought
>>through it...  At least I am still around to learn from this one.
>>     73,  Al  N5AIT

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