Power out spike

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  • Question
  • Updated 4 years ago
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  • (Edited)

I run at 16 to 20 watts out into a Alpha 8410. max drive as set in firmware by Alpha for my amp is 61 watts. I can set my power on radio up to 57 watts and never trip the over drive on my Amp. I did have a issue with the input going bad on the alpha. I sent it back and the input was repaired and several components were up graded as Alpha has been doing  with some know components in some of the newer amps.

I am starting to see the swr creep up on the input to the amp again. Alpha feels I have a spike out of the radio which is damaging the input?? I run a wave node watt meter with a history graph on the input to the amp and a second sensor on the out put. both sensors are connected directly to the amp with Ampenol double mail adapters. I see no spike at anytime but the swr according to the radio is a 2.00 and the wave node shows a 1.63 swr on the input when amp is keyed. 1.63 sounds reasonable but with a 2.00 the radio does reduce power about a watt at 23 watts? I have checked the jumper going to the amp and with amp in by pass the swr is 1.08 just like the amp sees at the antenna. all of this is on 75 meters.


Any one else having issues like this. I do run the audio in the DX1 modewith the mic gain never going red on me, with a pr40 and aTube MP/C preamp from the mic to the radio. all eq done in the radio and 20 db boost off sinc Time suggested that the cleanest signal was with the least amount of dsp gain.


ok anybody had this same issue, doncare if you have never had it just if you have?


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Dale KB5VE

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Posted 4 years ago

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Photo of Gerald - K5SDR

Gerald - K5SDR, Official Rep

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Official Response
I just spoke with the CEO of RF Concepts/Alpha, Ken Long.  He said that he was completely unaware of any issues with the FLEX-6500 and their amplifiers.  He also said that if there were real issues he would know about it.  I asked what he would recommend I say on our Community and he said to state that he "apologizes for any insinuation that may have been made to that effect by any Alpha employee."  I shared with him data that we collected today using a high speed DSO scope and he said that our data shows that the 6500 would not cause such a problem.  I sent him a copy of this thread and he said that he will research the matter internally.