A friend just built for me, an audible swr meter that indicates in morse.
It has several coded messages and also the actual swr. Quite a gadget but
works with very low power, 20 to 25 watts, maybe. As we know, impedance of
a device (antenna) changes with changes in the amount of power applied. One
can get pretty close, though.
73, de WA9RYF
----- Original Message -----
From: "Keith Barrett" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, March 19, 2008 8:47 AM
Subject: Re: valve radios revisited
: Hi,
:
: Could have been me you were referring to.
:
: Several years ago, a friend built several audible meters for me. They are
a
: small bbox with two so239 sockets, for input and output. There is a
switch
: to select forward and reverse power. One tunes for the highest tone when
: tuning transmitter or linear and lowest tone when in reflected mode. You
: can leave the swr mode selected as 0 reflected results in no sound, useful
if
: the aerial falls off.
:
: The circuits were published in The radcom sevferal years ago. I did offer
to
: send them to anyone who was interested at the time but got no takers.
:
: Not sure if the articles can be accessed from the RSGB webb site but I
: could probably send them to anyone interested. I think I may have a pdf
: somewhere but would need to try and find it.
:
:
:
: On 19 Mar 2008 at 9:45, Buddy Brannan wrote:
:
: > Hang on, some time ago there was an article for an audible SWR meter
: > by someone who used to be on this list. I'll have to dig it up.
: > On Mar 19, 2008, at 9:36 AM, Shaun Oliver wrote:
: > > I could I suppose build a tone osilator to run between the radio and
: > > the
: > > antenna, that wouldn't be too hard, take apart an old vswr meter and
: > > drop an osilator and speaker in in place of the guts of the vswr
: > > meter.
: > >
: > > Shaun
: > > web sites:
: > > http://www.myspace.com/blindmanshaunoliver
: > > http://blindman.homelinux.org/~blindman/
: > > skype: brailledude
: > >
: > >
: > > On 20/03/2008 12:27 AM, the old scribe known as Howard Kaufman was
: > > able
: > > to impart this pearl of wisdom:
: > >> I'd trust the attenuated rx more than the marked knobs. Something
: > >> like rain
: > >> might change the tuning, and your marks wouldn't be accureate. I
: > >> don't know
: > >> why you are trying to read the internal meter, rather than the watt
: > >> meter
: > >> outside the radio. If you do it that way, you have a system that
: > >> you can
: > >> use to tune any radio, not just one.
: > >>
: > >>
: > >> __________ NOD32 2959 (20080319) Information __________
: > >>
: > >> This message was checked by NOD32 antivirus system.
: > >> http://www.eset.com
: > >>
: > >>
: > >>
: > >
: >
: > --
: > Buddy Brannan, KB5ELV - Erie, PA
: > Phone: (814) 746-4502 or 888-75-BUDDY
: > Harnessing the power of Online Spending and Everyday Shopping to
: > Change Lives: See how, Together, We Can Change the World:
http://www.powermall.info
: >
: >
: > __________ NOD32 2959 (20080319) Information __________
: >
: > This message was checked by NOD32 antivirus system.
: > http://www.eset.com
: >
: >
:
:
:
: --
: No virus found in this incoming message.
: Checked by AVG.
: Version: 7.5.519 / Virus Database: 269.21.7/1335 - Release Date: 3/19/2008
9:54 AM
:
:
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