Bit - really HARD!
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
From: Perry Ballinger <w8au at SSSNET.COM>
To: BOATANCHORS at LISTSERV.TEMPE.GOV <BOATANCHORS at LISTSERV.TEMPE.GOV>
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
>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 Lysco....how 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....
>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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