Hi there,

Just had to re-live those great old Globe Chief 90 days too.  I even built
up a screen modulator for it so I could rag chew the local AM guys down on
75 meters!  That was way back in the 1950's and early 60's, before
sideband owned the whole phone band!

73,

Will, K4SAY
[log in to unmask]
 On Thu, 21 Nov 2002, Henry Brugsch
wrote:

> Hi Mike, you brought back some great memories. My first rig was a WRL
> Globechief 90a. I used to tune this using the power supply hum. When the
> meter just tickeled the far side, I knew |I was on 200 mills that needed for
> max output.
> This was back in 1959. I used that rig for some 15 years, or so.
>
> ----- Original Message -----
> From: "Mike Freeman" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Thursday, November 21, 2002 2:45 PM
> Subject: Re: Tuning an antenna
>
>
> > Hi!
> >
> > First, tube amplifiers hat "pi networks" to match them to the antenna.
> > Such a network could be designed to match a far wider range of SWR than
> > most transmitters and amplifiers can tolerate now (they're now
> > broad-banded and *expect* a narrow range of SWR).
> >
> > Second, there were meter-reading devices for the blind which could allow
> > us to tune just as accurately (if not more so) than could a sighted
> > person.  These were based upon two designs.  One was a Wheatstone bridge
> > with a current-interrupting mechanism and resistor with audio amplifier
> > across it so that when the bridge legs were unbalanced, one heard a
> > tone; when the legs were balanced, no tone was heard.  The potentiometer
> > in one of the legs was brought out to a braille scale and pointer so
> > that one could either determine the reading by adjusting for null noise
> > or adjust controls to match a wanted reading by tuning for a null.  The
> > second way was by using a voltage-sensitive oscillator (larger voltage,
> > higher pitch) and calibrating against a known voltage source with two
> > separate inputs which could be switched -- one across the meter in
> > question and the other going, again, to a potentiometer brought out to a
> > calibrated touch-readable scale.  One either tuned for lowest pitch
> > (tuning an amplifier for resonance) or highest pitch (maximizing output)
> > and one could determine the meter reading by matching the pitch with
> > that on the braille scale.  It should be noted that most latter-day SSB
> > tube amplifiers (either linears or finals on a transmitter) were running
> > Class B so that one could just tune for max output and be fine.
> >
> > But to the SWR.  These same meter-reading designs could be made to serve
> > to read SWR meters.  If one had a "match box", one could put raised
> > scales on the dials and either match the antenna(s) oneself using these
> > audible meters or have a sighted person do it and then one could write
> > down what the scales read for band and frequency range.
> >
> > And, then as now, there were automatic antenna tuners -- great motorized
> > contraptions.  I wish I had one.
> >
> > You could also use things like power-supply hum to adjust a final
> > amplifier and could adjust AM audio output by listening to the
> > modulation transformer.  You could balance out the carrier on an SSB
> > transmitter by using a transistor radio tuned to a subharmonic of the
> > signal.  I knew a guy who tuned his SWAN 350 using a transistor radio.
> >
> > In other words, things didn't *have* to talk and ingenuity was the name
> > of the game.  And there were crystal calibrators to determine 100 kHz
> > points (or down to 10kHz for some calibrators) and one could gestimate
> > between these points.  For instance, on a Drake TR-4, each revolution of
> > the tuning knob (which had a raised dot on the skirt) was 25kHz.  We
> > actually got pretty good at finding frequency.
> >
> > Bottom line:  where there was a will, there was a way and, frankly, I
> > think rigs were easier to operate forty years ago than they are now.
> >
> > Mike Freeman < K 7 U I J >
> > "All men tend to become that which they oppose." - Laurence van der Post
> > ----- Original Message -----
> > From: "Michael Ryan" <[log in to unmask]>
> > To: <[log in to unmask]>
> > Sent: Thursday, November 21, 2002 1:22 AM
> > Subject: Tuning an antenna
> >
> >
> > > Hi fokes:
> > >
> > > Just have a question regarding blind ham tuning an antenna in the
> > early days.
> > > How was it accomplished? I'm pretty sure there were no talking SWR
> > Meters
> > > or automatic antenna tuners.
> > > Did sited fokes build antennas for the blind ham for the exact band
> > and
> > > then was a "let her writ" attitude adapted due to the tubes in the
> > > transceiver?
> > >
> > > Thanks and 73:
> > > Michael VO1RYN
> > >
> > >
>