[Boatanchors] Lysco 600S Loading

[Bill Stewart]

Hi Vic,
Thanks for the info on the Lysco. Just by looking at the wiring and some of 
the solder joints, I knew that the previous owner had done some fiddling 
around. However, it did have some output on all bands and was hoping it 
would work ok on the antenna. I'm gonna have to check it more carefully and 
see whets been changed. I did notice that the 18 ohm meter resistor is 
missing.....sooooo no idea just what the grid current is...yet. I guess 
that's a good place to start checking the wiring. Thanks for the other 
ideas. Now, where's that magnifying glass???...73 de Bill K4JYS
----- Original Message ----- 
From: "Vic Rosenthal" <vic at rakefet.com>
To: "Bill Stewart" <bstewart at ipass.net>
Cc: <boatanchors at mailman.qth.net>
Sent: Tuesday, February 01, 2005 4:30 PM
Subject: Re: [Boatanchors] Lysco 600S Loading


> Bill Stewart wrote:
>
>> With the Lysco working, I was anxious to get it paired up with a HQ-129X 
>> and
>> get to pounding some brass. However, since the output is single ended and 
>> has
>> no antenna loading cap., I couldn't get the final to load high enough to 
>> get
>> much output. Into a cantenna I get anywhere from 60ma to 75ma (at the 
>> dip) on
>> 1.8, 3.5 & 7 mc. It made it up to around 100ma at 28mc. When I connect my
>> 80/40 mtr inv. vee I get even less plate current and the output power is 
>> 5
>> watts or less. I did hang a 900uuF var. cap across the output to gnd, but
>> really didn't t seem to help. The spec sheet says the PA should be around
>> 125ma. What do I need to do to get it to load and give more output.
>
> Looking at the schematic, it appears that the output circuit is just a 
> parallel tuned tank with a tap up from the bottom of the coil.  Some 
> models seem to have a LP filter between the tap and the output.
>
> Are you getting the correct amount of grid current?  If so, and if the 
> plate current dip is very deep, then maybe the coil tap is not set 
> correctly.  Could you (or a previous owner) have changed any of them? 
> Insufficient loading could mean that the tap needs to be moved up (away 
> from ground) on the coil.  Another possibility could be a bad capacitor 
> (open or changed value) in the LP filter. You might try disconnecting the 
> filter and taking the output directly from the coil tap to test this.
>
> -- 
> 73,
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco
>
>
>