Date: Sat, 8 Apr 2017 18:04:16 -0500
From: Joe <nss@mwt.net>
To: amps@contesting.com
Subject: Re: [Amps] New Amplifier
Really makes ya think twice about home brewing up an amp with some of
those new transistors. Like one I saw the other day was also 100% duty
cycle 1500 Watts OUTPUT, for 250 bucks.
Then add the fact you could in reality just add whatever band pass
filtering needed for purity standards because no output matching is
needed when it states it can run into a 65 to 1 SWR!
Wow!
Joe WB9SBD
## dream on. It wont run any power into a 65:1 swr. It will just throttle
back to
virtually zero watts, so it doesnt blow its brains out. Ultra fast SWR
protection they state.
They dont state what power it will run full bore..at say a 2:1 swr..or a 3:1
swr.
Thats what you need to know.
No built in auto tuner either. So you either buy an aftermarket, fully
automatic 2kw rated
tuner, or use a manual tuner. Either way, you wont get the lightning fast
bandswitching, if the
tuner is required on both bands. You could, if it had enough smarts to
engage, or disengage the
outboard tuner, and the same tuner was tuned for just one band.
No mention of IMD specs. It should be fairly good, since the devices are being
run at half power. That
plus they have done it right by using 6 x diplexers, instead of the usual 6 x
LP filters. With any LP filter, the
harmonics get reflected back to the output of the pa..making ind worse. The
harmonics dont get routed to ground, nor do they get absorbed
by the LP filter. With a diplexer, the output of the pa is fed to both the
input of a high powered LP filter, and also the input of a
low power HP filter. Output of lp filter is routed to ant. Output of HP
filter is routed to a 50 ohm dummy load.
High ant swr will make imd worse.
100% ICAS is pure bs. 100% ICAS just means it is capable of hours on end
of ssb operation, and also cw operation.
And probably RTTY and FM operation, as long as the amp is not in TX mode for
very long, like probably less than 30 secs.
Im not a rtty operator so will defer to Bill, as I dont know the typ overall
duty cycle for typ casual rtty ragchewing vs contesting.
Would be interesting to know how much po it will run, brick on key, 100% duty
cycle... which is what it really should be capable
of for $7000.00 The pair of transistors they use are fully capable of doing
just that. Any 3 kw CCS switching power supply is
a piece of cake these days, since the telcos have been using 3 – 3.3 kw CCS
switchers for 15 years or more now. The fans,
cooling, heat sinks is another matter..whwich may be the limiting factor.
Watch their video, you can hear the fans start screaming, part way through
the video. What these various amp makers
should spec, is an A weight noise spec, done from 1 meter away. Even that
doesnt tell the whole story. Fan or blower noise
at a lower pitch is more tolerable than a higher pitch.
I would like to know what the eff is when the amp is run at lower power, like
say 500-1000 watts....and if the imd is any lower,
when run at lower power.
Jim VE7RF
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|