Apparently Ameritron amps still use BI-state EBS........ while Alpha .Acom,
and now Emtron, all use TRI-state EBS.
I tried a HB BI-state EBS scheme a long time ago,, and did not have good
success on VOX ssb.
Qst ran some articles using BI state EBS in the mid 70's. The idea was to
bias the tube off between
dots and dashes... when using QSK.
Since I ran VOX ssb, and normal idle current was low to start with on a GG
amp, I did not realize a lot of heat savings
only more distortion, when it switched from cut off bias to normal bias.
On CW.. I instead just increased the bias voltage, and lowered the idle
current to just 10 ma.
Do these TRi -state EBS bias schemes actually work on SSB ?? [ I use a
noise gate on the audio as well.]
Will they toggle between 'pre-bias' and normal operating bias.... between
syllables... or just between words ??
If they toggle between words, I still can't see much use for em. My VOX
delay is typ aprx 375 msec.
IE: I finish talking.. then Vox drops out. Where is this heat savings ??
[ I can see it on PTT / Footswitch style operating,
but that's about it.] I'm referring to VOX SSB here,, NOT PTT.
I don't even see EBS mentioned, in any of the recent / latest ARRL handbooks.
later..... Jim VE7RF
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