How about this then: in the micor there is a 4 cavity filter on the output of the exciter. If I tuned 3 of those cavities properly and detuned the last so it acts as an -16 dB attenuator would that work in obtaining my 10 mW input into my mobile amp without creating any problems?
On 8/23/07, Kevin Custer <[EMAIL PROTECTED]> wrote: > > Jesse, > > While your method may work, it likely won't be clean; not ever a good > thing, especially where a repeater transmitter is concerned. The Micor VHF > transmitter, like most FM transmitters, uses Class C RF amplification. When > a Class C amplifier is under-driven, or turned down below about 50 or 60% of > its capability, it can become unstable - spurious. It is much better to > select the number of stages, and properly drive them to create the amount of > power output required. This also results in the best efficiency, and since > you won't have excess power to burn in a solar situation, the method I > suggest is likely better. > > Jesse Lloyd wrote: > > That PA mod is awesome. I was considering knocking down the power out of > the exciter to 20 mW by increasing the value of a couple resistors, and then > feeding it into a 40 Watt M100 PA. From there I have the ability to vary > the output power from 5-40 watts (ish). > > Jesse > > > > On 8/22/07, Kevin Custer <[EMAIL PROTECTED]> wrote: > > > > Jesse, > > > > You can put a toggle switch on the B+ line going to the Audio PA, this > > will cut several hundred mA of current draw from the Class AB audio section, > > and allow it to be connected/turned on when service is required. > > > > Since you are working on a VHF unit, you can review the mods on this > > site where I took a 110 watt PA, hack-sawed it in half, and made a 5 to 12 > > watt PA that is very power efficient: > > http://www.kuggie.com/ahra/hmftinfo.html > > > > I've also been successful in doing the same with only one transistor > > (the controlled stage) and created a .5 to 2 watt PA. > > > > >
