Discussion in 'Amplitude Modulation' started by KI5OMM, Jul 2, 2021.
In the Part 97 world, sure, but I doubt you'll see one at a hamfest.
nobody ever made an image like this for a Nautel
The intrigue is there, but only if a fellow is interested in MOSFETs and A to D conversion and chips with firmware that switch the FETs on and off according to coded firmware logic. Each 50 KW rig is made to order and it's taking over six months now. I don't know how long Nautel supports their rigs with parts and board inventories. I always heard Harris wasn't so good. If anyone is still running a DX50, I think they're on their own. I also heard that even if you have a 3DX, if you call Harris (or is it GatesAir now) you get a guy who reads the manual to you over the phone. And of course, any solid state rig is more vulnerable to lightning damage than the tube rigs were, but they're so much cheaper to operate. Broadcasting has been going the way of ham radio with plastic radios. Nowadays everything between the microphone and the ATU is either beyond me, or of no interest.
Just as an experiment, I used the external ALC “mod” (negative voltage applied to the ALC loop) with a slop bucket Icom IC-751A (circa 1988 or so). Audio was fed via the back bypassing the mic preamp:
With a voice like that you can't lose.
Sterile is a good descriptor for that Nautel 50.
It doesn't even have any meters or adjustments showing.
You get a touch screen for everything.
That would be hard on an engineer missing any fingers.
Maybe they could lick it...
I remember a fellow on 75M years ago who ran his audio through the 600 ohm rear input (used for phone patching), of a Kenwood TS-440. He had excellent audio to the point I thought he was using a tube rig. He said by doing this he was able to bypass all the speech processing and ALC that was at the MIC input of the rig.
The problem with many plastic radios is that the RF carrier driving a leenyar, is usually unstable. Set the exciter cxr at 20 watts and over the next several minutes it will drift down. You have to keep bringing it back up. Then on the next xmission, boom your drive is twice what it should be. Having to constantly futz with that makes running a plastic radio suck even more than usual. Not all do it, but I'm told Kenwoods and Yaesus do.
That's exactly how I run (ran) my Eico 730 modulator used with the Eico 720 that I use(d) on 10m. Even though the "phone patch" input to the 730 is unbalanced through an RCA jack, I fed the 500/600 balanced line output from the audio rack directly to it, simply grounding one side. That works excellently with full fidelity.
The ts440 and the Icom 735 had that problem, the power would go up as things warmed up.
I think someone had a fix for that, but I never did it.
The new radios are very stable in output.