Hi,

You sure can use a noise bridge to tune an antenna tuner.  Just make
sure you know where the 50 ohm setting is on the bridge and  then tune
the tuner for a sharp null in the noise.  One caution:  be darned sure
you remove the bridge from the line before you transmit or you will
have a noise bridge that doesn't produce a sound!

If you are using one of the rigs of today with an automatic antenna
tuner you can tune by listening to the motor and when it stops, the
antenna is matched.  You don't know how good the match is of course,
but it's a way to do it without a lot of hightech equipment.  When you
do this without any speech or similar readout, it isn't a bad idea to
move up and down the band a bit just to get an idea of how much your
swr is changing as you shift frequency.  Once you get one of these
things tuned up on a band, it really is a good idea to check the match
with the auto antenna tuner whenever you change frequency very much.

I do remember the rigs with a sweep tube amplifier.  They weren't quite
as forgiving with swr and it was always a good idea to tune the thing,
regardless of how you did it, very promptly.  If you didn't, you really
needed a good supply of new tubes.  <grin>  Those things could blow in
a hurry if you weren't careful.

Don W6SMB



On Thu, 21 Nov 2002 19:17:41 -03-30, Michael Ryan wrote:

>Can   a noise bridge which was once used on an old heath kit
>HW-12 be used in conjunction with an antenna tuner for reading SWR?
>I will try and describe it.
>It has a switch on the lower front which slides back and forth to the left
>or right for turning on or off and a flat roguery knob next to the
>switch.  The connectors for antenna and so on are on the top.  It also has
>a round raised speaker.
>I would also like to know what to look for, when it comes to the power
>supply hum, when the rig is loaded up for maximum out put.
>
>Thanks all:
>Michael