[AMRadio] Amp advice

W5OMR/Geoff w5omr at satx.rr.com
Sat Oct 29 17:10:56 EDT 2005

Mike Dorworth,K4XM wrote:

>It seems we're back to where we were. In theory the maximum carrier is
>limited to half the tube dissipation. i.e 250 watts. The power supply is
>good for about half that amount. This means the Ranger can put out at MAX
>around 12  to13 watts. The carrier about 125 watts, the pep output about 500
>watts. Your ability to buy power transformers and tubes may vary.. Hope this
>helps.. Mike

Sounds good. 

Were it me, and that was the way I had to go, I think I'd stiffen up the 
power supply as best as possible.
Depending on the capabilities of the plate transformer, maybe stick 
another 3-500Z in parallel to the one that exists, and run the amp to 
300w of carrier, and let the positive peaks fill the 1.5kW pep 
envelope.  It might even take a bit more drive from the Ranger, so 
instead of an attenuator pad for RF on the amp input, maybe vary the DC 
voltage on the plate, or the screen voltage of the 6146 in the Ranger, 
adjusting the level to whatever is required.

Remember, the less load drawn through the secondary of the stock Ranger 
modulation transformer, the better the audio is going to sound, stock 
out of the Ranger.
The reason being, there's less plate current being drawn through the 
secondary of the modulation transformer, and therefore less chance of 
core-saturation, cause the hysteresis curve of the transformer not to be 
as linear as possible.

73 = Best Regards,

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