Amps
[Top] [All Lists]

Re: [Amps] AM Downward Modulation

To: "'harold b mandel'" <ka1xo@juno.com>, <amps@contesting.com>
Subject: Re: [Amps] AM Downward Modulation
From: "Gary Schafer" <garyschafer@comcast.net>
Reply-to: garyschafer@comcast.net
Date: Thu, 13 Apr 2006 22:20:20 -0400
List-post: <mailto:amps@contesting.com>
Some radios have the alc active on AM and allow you to set the carrier
higher than the 25% level. As the peaks reach the 100 watt mark the alc
reduces the gain which reduces the carrier level and you see the output
meter kick downward.

Some radios work fairly well this way and is the reason some are specked at
a higher carrier level than the 25% mark. However most will sound better if
the carrier is set to 25% of full output or lower.
Some radios sound awful when the alc kicks in.

If the carrier is set lower than the 25% level you can actually modulate the
rig at greater than 100% with little to no distortion as long as the
positive peaks are kept below the maximum pep capability of the radio.

With the balanced modulator in the radio, going over 100% in the negative
direction does not cause distortion and splatter as it does with
conventional modulation. The modulation just "folds over" and reverses phase
when going over on negative peaks.
So the only thing you really need to worry about is keeping the positive
peaks below the pep capability of the radio.

73
Gary  K4FMX


> -----Original Message-----
> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
> Behalf Of harold b mandel
> 
> What does it mean when a Kenwood TS-450s/AT
> downward modulates in AM?
> 
> The RF Power actually decreases in both average and peak
> settings.
> 
> The waveform fills with speech, but the envelope shrinks.
> 
> Anyone ever see this or know if it is normal?
> 
> All other modes transmit normally.
> 
> Thanks,
> 
> Hal
> W4HBM
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps


_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps

<Prev in Thread] Current Thread [Next in Thread>