[TenTec] Aux I/O connection

Bob McGraw - K4TAX RMcGraw at Blomand.net
Sun Apr 19 20:48:54 PDT 2009


Remember, I said "sideband bandwidth".  A measurement of each sideband and 
one will see that it is less than current SSB transmitters.  I run a nice 
digital filter with a sharp cut-off at 2.4 KHz so my audio response is 40 Hz 
to 2.4 KHz.  The sideband is then carrier plus 2.4 KHz max.  In today's SSB 
transmitters with a 2.4 KHz bandwidth filter, the TX BFO is on the slope of 
the filter such that the transmitter audio response is 300 Hz to 2.7 KHz 
{300 Hz + 2.4 KHz = 2.7KHz} so the SSB signal is equal to carrier frequency 
+ 2.7 KHz bandwidth audio so it is wider than my AM sideband by 300 Hz.  In 
SSB one looses the lower 200 to 300 Hz of the spectrum.  Of course there's 
not much energy there from the human voice but the upper end is sure 
present.

Oh I must admit, I cheated on the wording with malice just to see whom I 
could pull out of the woodwork.  It worked!  Just being a bit picky.

Bob, K4TAX

----- Original Message ----- 
From: "Martin Ewing" <martin.s.ewing at gmail.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Sunday, April 19, 2009 8:19 PM
Subject: Re: [TenTec] Aux I/O connection


> On Sun, Apr 19, 2009 at 3:00 PM, Bob McGraw - K4TAX 
> <RMcGraw at blomand.net>wrote:
>
>> ...  And oh by the way, my AM transmitter doesn't use any more
>> sideband bandwidth than current technology SSB rigs and in many cases it
>> uses less.
>>
>> 73
>> Bob, K4TAX
>>
>
> I've been around since the AM era, myself, but I don't see how  DSB AM
> doesn't take at least twice the bandwidth of  SSB for the same voice 
> input.
>
> 73 Martin AA6E
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