Amplitude Modulation in Central Florida

[Robert & Linda McGraw K4TAX]

Correctly stated Pete.

Today's 100 watt PEP radios on AM should run only 25 watts of carrier. Thus 
when modulated 100% the PEP value of the AM signal is 100 watts.  I find all 
too often folks are running more power on the 100 watt radios than they 
should.  The result is poor modulation, splatter, distortion not to mention 
the potential risk of failure.  If in doubt, look at your signal on a 
monitor scope.  I'll be you'll be surprised at what you see.  Are your 
modulation peaks actually making 100% positive?  At 30 to 50 watts of 
carrier I doubt it.

Remember, for AM operation carrier power x 4 = PEP power.

Thus:

25 watts AM = 100 watts PEP
50 watts AM = 200 watts PEP
375 watts AM = 1500 watts PEP

Let's all be legal and clean.

73
Bob, K4TAX



----- Original Message ----- 
From: "Peter A Markavage" <pmarkavage at JUNO.COM>
To: <HEATH at LISTSERV.TEMPE.GOV>
Sent: Saturday, January 07, 2006 1:40 PM
Subject: Re: Amplitude Modulation in Central Florida


> The 756's are rated at 40 watts max. on AM. However, the recommended AM
> power output is about 25 watts. At 40 watts, distortion products can be
> noticed on the carrier, and if you do long key-down transmissions, you
> can probably kiss your finals goodbye.
>
> Pete, wa2cwa
>
> On Fri, 6 Jan 2006 12:41:53 -0500 Bob Hardie <bhardie at WTTA.SBGNET.COM>
> writes:
>> Okay guys.  I'm convinced.  I want to do AM too.
>>
>> Howsumever, I do have an AM problem right now too.   My Viking II is
>> not
>> up and running yet.  Just received it from my wonderful lil brother,
>>
>> W5SJ, Bill Priakos, while on my holidays/vacation trip back home.  I
>>
>> need to put it back together and finish fixing it up.  It will look
>>
>> great/work great... I hope/ too.  No way by tomorrow.  Only thing I
>> can
>> put on AM is my Icom 756.  It puts out 50 watts on AM, I think.
>> SOUNDS like fun though and even if I sit, drink decaf and just
>> listen,
>> I'm gonna try to be there. Just like in the 50's and 60's.    Bob
>> W5EUQ/ Tampa, FL.
>>
>> Bob Hardie- CSRTE
>> Chief Engineer
>> WTTA  (TV)/DT WB38
>> Direct 813-880-8182
>> Fax 813-880-8106
>>
>>
>
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