[Amps] dentron tuned input

[Gudguyham at aol.com]

In a message dated 3/11/04 01:53:37 AM Eastern Standard Time, 
ne2i at optonline.net writes:


> any one have any ideas on how to add a tuned input to a dentron clipperton L
> I know about the cm2 but they are exceedingly rare...
> supposedly the 4 572b's have a combined input impedance of 75ohms but
> the mkV dont like it even with the tuner on...
> 
> Thanks
> George NE2I
> 

Hi George, It always amazed me how the CM-2 input matching "black box" was 
sold to match the input of all the Dentron amps that did not have a tuned input 
circuit.  I do not know anything about it, but perhaps you need to make 
adjustments on the CM-2  to match the individual amps to a rig.  I do not think so 
though, anybody know?  Anyhow, I like to always look for the "easy way out" of 
problems, so once when I had to use my Swan Mark I amp with a solid state 
radio, I could only muster about 600 watts out form the amp that should do a KW 
output.  I know that the solid state radio was folding back due to the high 
input SWR.  I know an input circuit of sorts was needed.  Being lazy, I grabbed 
hold of my little MFJ 16010 antenna tuner and inserted it in between the rig and 
the amp, after finding the right "tap" on the inductor and tweaking the 
little air variable cap a bit, there was my KW on all bands from the solid state 
radio to the Swan amp.  I noticed that on almost every band the tap was the 
same, and only required a tweak on the air cap to get a perfect match every time 
and full power out from the amp.  I simpley tuned for max smoke on the output 
meter and the exciter was happy as a Lark!  BTW  I paid $8.00 for the 16010 at 
a Flea Market.  The tuner in the radio should provide the same matching, but 
the way the input impedance varies on a "tube" as an input causes the antenna 
tuner to endlessly "seek", it finally stops, but the match is still not right.  
On the 16010 manual tuned, you will easily see a match using MAX smoke as an 
indicator.
Good Luck 73 Louie