[Moon-net] Two-meter power spikes ruining TE Amplifiers?

[Edward Cole]

Never had a problem using my FT-847 with my RFC 2-315 linear amp.  It 
takes 40w drive as normal input, though.  The spike you cite is 
usually attributed to when the power button is pushed, not the PTT 
function.  You may be overly concerned.

You should be using a sequencer, of course, but that usually enables 
the PA before enabling the exciter Tx.  I have yet to test an idea 
for the FT-847 using the Tx inhibit pin on the accessory jack for 
final sequence control of the exciter, but this may be a solution (if 
their is a problem which I am not convinced of).  I have been using 
this combo on JT65 eme since 2003.

I have heard from others that the TE amps are sensitive to 
overdriving and finals failure, but I have no direct experience with 
them.  I recently tried to purchase one on e-bay but got outbid in 
the last minute of the auction.  I'm working on my 8877 PA, in any case.

At 05:22 AM 12/14/2007, Cristofori Concerts wrote:
>I wonder if anyone has nad experience with this question?  I have
>ordered a new TE Systems 400 watt (c. 20 watts in,) amplifier to use
>with my FT-857, and just picked the following post on the FT-857 board:
>
>"Don't know about final bias on 2m and the -857, but apparently this
>radio
>really puts out a power spike when keyed up on 2m, far above rf pwr out
>setting. Seems the rf pwr out is alc controlled, etc.. Not a big deal
>unless
>you're using an amp at max input limits. I understand the TE Sys amps
>sometimes get taken out by such a spike, and not just fm -857's."
>
>Many thanks for any advice about how to avoid potentially blowing out
>an expensive new amp.
>
>73,
>
>Martin, KC3RE
>
>
> 
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73,
Ed - KL7UW
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