[Amps] 1000 Watt Limit to 1500 OUT

[Robert B. Bonner]

That is correct

-----Original Message-----
From: Gary Schafer [mailto:garyschafer at comcast.net] 
Sent: Sunday, October 15, 2006 8:33 PM
To: 'Robert B. Bonner'; amps at contesting.com
Subject: RE: [Amps] 1000 Watt Limit to 1500 OUT



> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
> Behalf Of Robert B. Bonner
> Sent: Sunday, October 15, 2006 2:47 PM
> To: amps at contesting.com
> Subject: [Amps] 1000 Watt Limit to 1500 OUT
> 
> The old legal limit was 1000W DC as measured on the meters.  There was no
> written PEP number.  This was something "The marketing department" came up
> with to make things sound bigger.  The SSB position on all the amps, was a
> power booster to give the amps MORE zip to bring the average power up to
> try
> and meet the 1000W DC limit.  HOAKIE, especially as it was technically
> illegal to tune the amps up in the SSB positions in the first place.

Not so hoakie but very practical. The ssb position on those amps like the
SB220, Drake etc. raised the plate voltage and plate current to maintain the
same plate load impedance that you had when you tuned up in the cw position.
It effectively let you tune up for maximum pep without going over the 1kw
input.

> 
> It was virtually impossible to measure 1000W "average" input in the SSB
> mode.  "They" came up with station monitors to try and do it.  "They" came
> up with slow meter movements to indicate lower power, the feds came up
> with
> a meter speed specification.  There's never been a clean way to measure
> INPUT POWER in SSB.  It virtually takes the voltage and current meters fed
> into a computer and instantly calculate and average the readings.
> 
> SO along came the 1500W output law.  It has been mentioned here this was a
> power lowering for us. I agree and disagree, IN AM it was a considerable
> power lowering.
> 
> 1000W DC input could easily make 600 Watts carrier. Modulate that carrier
> and you have 2400Watts PEP output.  This is a hell of a rig.  Proof is the
> Collins KW-1.
> 
> Now at 1500 PEP output and the 4:1 factor of PEP to carrier you legally
> have
> a 375 Watt carrier limit to make 1500 PEP.
> 
> However this is not the case in CW 1500 Watts output is easy to measure in
> CW.  Key the rig and PEP =Average and 1500 watts comes screaming out the
> tailpipe.  A power increase from 600 or so to 1500 watts.  That's a
> considerable power increase.
> 
> However once we flip to SSB we're back to measuring that variable PEP
> thing
> again with computers and metering/averaging formulas.  Fortunately the
> feds
> will let us use a quality Peak Reading Wattmeter to do it.
> 
> We can tune up in CW to 1500 watts and flip to PEAK READING and just don't
> go over the number...
> 
> I have found approximately what used to be a 2KW amplifier is now a 2400
> Watt amplifier.  I have not had to "type accept" an amp as Tom has.
> 
> I feel we got a 900 Watt bump on CW and a potential "300 Watt" bump on SSB
> from the power measuring change.
> 
> Sincerely,
> 
> BOB DD

Look at the plate current or average power as read on a bird 43 and compare
that against the pep that the rig is running. You may be shocked at the high
ratio on ssb.

73
Gary  K4FMX