Geoff/W5OMR writes:
I'm soliciting ideas on grid inputs on a 4-125. Thoughts?
Many ways to do this, Geoff, as I'm sure you know. What worked out well for me on the FR deck in the big PDM rig (pair of 7527A's in parallel) was to load the grid with ~2500 ohms non-reactive (a bunch of non-X 7W resistors in series) and match it from a 50 ohm source with a T network - two series variable caps with a tapped/switched inductor from their junction to ground. This allows me to tune the grid circuit from 160M - 10M, and the resistive loading is good for stability. Since to drive a class-C amplifier we LIKE harmonics there is no liability employing the T network. It takes about 25 - 30W on the low bands, more as the network becomes lossy at higher frequencies to get 30 mA grid current. (I use my TS-440S as the RF exciter, so no problem there). For a single 4-125 you will need less, of course.
GL, -Larry/NE1S ______________________________________________________________ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
