[Amps] Why hasn't solid state replaced tubes?

dj2001 at mn.rr.com dj2001 at mn.rr.com
Wed Mar 5 09:04:10 EST 2003


>  > I use a Nye Viking RF3000, RF power monitor.  I'd have to dig out the
>>  book to be sure.  I checked it against my Bird and it seemed close
>
>I'm not sure how the Nye is. Many not-fast-enough peak meters agree with
>really fast meters on things like voice, but will miss 2-10mS pulses.


I also have a Signal Crafters which is the meter I used to see the 
spike in the KWM380.  Maybe I'll try it on the 775.  I'm not looking 
for trouble but if the thing is putting out spikes I sure do want to 
know about it.  In fact I really don't like owning and operating 
radios that have that weirdness.  Funny they (MFG's) can't design and 
build a radio that has all the stuff fixed from the past twenty some 
years.

Tom I checked your web site out, lots of good info there.  It's bookmarked.

Dale J.





>That was a major problem when finding meters to test medical generators that
>put out a sharp pulse on 27.120Mhz. I even went through a long back and
>forth exchange with Coaxial Dynamics and Bird until we modified the meters.
>
>One cheap meter that is really fast and holds well is the meter in ATR30's
>and the Ameritron wattmeter. (Not the MFJ meters, they are all junk. They
>don't even read a steady SSB "helllloooo" correctly.) It actually can catch
>relay sequencing in amplifiers, where the tiny arc causes a broadband click.
>The broadband transient shows as an SWR spike (I can hear it on a receiver
>also) becuase it has energy from d-c to light, being caused after the
>pi-net.
>
>>  overshoot.  For a 100 watt output transmitter I was getting peaks
>>  beyond 200 watts.  I think there was somthing wrong in the alc, I
>>  dident have it very long.
>
>My IC706 mobile puts out up to 180w pulse depending on supply voltage, even
>when cranked down to 10 watts. My FT1000D will overshoot also if I don't
>keep the drive control down.
>
>This beats the heck out of tank components, and even can cause tubes or tank
>circuits to arc. I had to disconnect the overdrive protection in my mobile
>amplifier because of the 706's bad overshoot.
>
>73 Tom
>
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