|[AMRadio] Halli HT37 Phasing Mod problem|
collinsradio at comcast.net
Tue Nov 27 22:18:11 EST 2007
Gary, my late father-in-law (W3MGU) used a loud mechanical clock with a
microphone to listen to the other sideband. He then adjusted the sideband
supression for the weakest tick-tock.
Dave, W3ST - W3CRA
Collins Radio Association
Join the largest Collins group in the world
Nets on 7208 at 4:30 EDST every day and
Monday at 3805 at 8 PM EDST
----- Original Message -----
From: "Gary Schafer" <garyschafer at comcast.net>
To: "'Discussion of AM Radio in the Amateur Service'"
<amradio at mailman.qth.net>
Sent: Tuesday, November 27, 2007 9:16 PM
Subject: RE: [AMRadio] Halli HT37 Phasing Mod problem
> If you are trying to align it using a tone and looking for a flat response
> on the scope and you have any hum in the circuit you will never get it
> aligned. Hum can come from poor filter caps in the power supply or audio
> leads picking it up.
> The best way that I have found to align phasing rigs is to talk into the
> mike while listening to the opposite side band and tune things for minimum
> (best side band suppression). A nice long ooooooh works good. You will
> to switch side bands and do the same on the other as they interact. You
> tune it for really great suppression on one side band while the other one
> won't be so great.
> Find the point where the suppression is nearly equal on each side band
> listening to the opposite side.
> Sometimes the Rf phasing coil will have little effect when tuning it. It
> depends on how tightly it is coupled to the next stage.
> Gary K4FMX
>> -----Original Message-----
>> From: amradio-bounces at mailman.qth.net [mailto:amradio-
>> bounces at mailman.qth.net] On Behalf Of DOXEMF at aol.com
>> Sent: Tuesday, November 27, 2007 11:59 AM
>> To: amradio at mailman.qth.net
>> Subject: [AMRadio] Halli HT37 Phasing Mod problem
>> I have been trying to get this like new HT37 on the air for awhile.
>> The audio phasing modulator has been near impossible to properly
>> espeially using the manual instructions.
>> So far have replaced a leaky low pf brown drop silver mica
>> that corrected some of the problem but still am not able to get a
>> phased output from the modulator.
>> The audio seems ok up up to the rf stage where it won't align. The
>> carrier osc is on freq ok but the carrier phasing adjustments do not work
>> Where would be a good location to apply a ballanced audio signal to
>> bypass most of the original circuit?.
>> Has anyone come up with an alignment procedure using modern test gear?
>> Our Main Website: http://www.amfone.net
>> AMRadio mailing list
>> List Rules (must read!): http://w5ami.net/amradiofaq.html
>> List Home: http://mailman.qth.net/mailman/listinfo/amradio
>> Help: http://mailman.qth.net/mmfaq.html
>> Post: mailto:AMRadio at mailman.qth.net
>> To unsubscribe, send an email to amradio-request at mailman.qth.net with
>> the word unsubscribe in the message body.
> Our Main Website: http://www.amfone.net
> AMRadio mailing list
> List Rules (must read!): http://w5ami.net/amradiofaq.html
> List Home: http://mailman.qth.net/mailman/listinfo/amradio
> Help: http://mailman.qth.net/mmfaq.html
> Post: mailto:AMRadio at mailman.qth.net
> To unsubscribe, send an email to amradio-request at mailman.qth.net with
> the word unsubscribe in the message body.
More information about the AMRadio mailing list
This page last updated 24 Jan 2018.