[Boatanchors] reduce power on ranger

[Bill Cromwell]

On 12/23/2013 11:06 PM, manualman at juno.com wrote:
> Ya, the 300V CCS I quoted from memory was running the 2E26 in a audio amp
> or modulator running Class A1. Running it as a plate modulated Class C
> phone RF amplifier, the CCS should be around 400V. Since the intent is to
> run the Ranger at a much lower output power, it makes sense to run the
> plate voltage (the modulator tubes can stay on the high voltage -
> provides more head room) on the lower voltage supply. It worked for me
> without the need for external noninductive resistive pads. As someone
> else pointed out, there are numerous documented ways to reduce output
> power on a Ranger and similar type transmitters. Whatever suites your
> fancy.
>
> Pete, wa2cwa
> http://www.manualman.com
>
>

Hi,

Apparently some hams get away with running 2E26s at around 600 volts on 
the plate for CW operation. I know there are other things to consider 
with AM. I like to be more conservative and I am thinking 600 volts is 
on the ragged edge for a 2E26. What I have right now with my dilapidated 
DX 100 is a pair of 2E26s in the 6146 sockets and the plate supply 
rerouted to the 300 volt power supply. The bias is still set for the 
6146s at minus 75 volts so the 2E26s are deep into cutoff class C. I'm 
getting 8 to 10 watts output on 160 meters. If the transmitter survives 
I will be using it QRP in the Stew Perry this weekend. Changing the bias 
would likely get me some more power. It's just a temporary lashup to get 
me into the Stew this weekend. There are no audio or modulator tubes in 
the DX-100 so the low voltage supply has adequate reserve power.

For my Ranger I just cranked the drive down and retuned the plate. I 
don't know what else would require adjustment to operate with reduced 
drive for AM. I know that does not address the original post. That 
fellow wants to operate AM with his Ranger and an amp. I will have to 
defer to hams who actually operate AM <grin>. In MY mode reducing is 
just too simple.

73,

Bill  KU8H