Colin,
The ones I've seen measure current, among other things, so you can't assume
anything. Usually, there's a switch that selects what the meter measures
(output power, plate current, grid current, ALC, and who knows what else).
It depends on the radio.
Steve
----- Original Message -----
From: "Colin McDonald" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, March 18, 2008 15:34
Subject: Re: tone osilator.
> ah ok.
> So a typical meter doesn't reference a certain voltage or current to
> ground
> usually?
> 73
> Colin, V A6BKX
> ----- Original Message -----
> From: "Steve Dresser" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Tuesday, March 18, 2008 9:34 AM
> Subject: Re: tone osilator.
>
>
>> Colin,
>>
>> That only works if one side of the meter operates at ground potential,
>> but
>> not of both sides of the meter are above ground, which is usually the
> case.
>> Besides, I don't think you want voltage from the key circuit on the same
>> jack as your oscillator because of stray capacitance that might be
>> introduced in the jack.
>>
>> Steve
>>
>> ----- Original Message -----
>> From: "Colin McDonald" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Tuesday, March 18, 2008 10:18
>> Subject: Re: tone oscillator.
>>
>>
>> > that could work yep.
>> > I think the straight key jack is a regular phone jack, meaning it has
> just
>> > the tip and sleeve connections.
>> > If a person were to replace that jack with a TRS jack, with the extra
> ring
>> > connection, you could easily use the sleeve and ring for the tone
>> > oscillator
>> > and allow the sleeve and tip to remain the CW key circuit.
>> > I think the use of a diode in either the tone oscillator circuit or the
> cw
>> > key circuit to prevent any ground loops might be wize as well.
>> > Though i'm not sure how that would work.
>> > 73
>> > Colin, V A6BKX
>> > ----- Original Message -----
>> > From: "Shaun Oliver" <[log in to unmask]>
>> > To: <[log in to unmask]>
>> > Sent: Tuesday, March 18, 2008 8:03 AM
>> > Subject: Re: tone oscillator.
>> >
>> >
>> >> perhaps without drilling holes in teh rig one could modify the morse
> key
>> >> jack to provide power for such a device?
>> >>
>> >>
>> >> On 19/03/2008 12:37 AM, the old scribe known as Martin McCormick was
>> >> able to impart this pearl of wisdom:
>> >> > One thing I saw on an old Heath Kit Warier linear which
>> >> > had been outfitted with an audio tuning device was a
>> >> > quarter-inch stereo headphone jack on the rear of the chassis.
>> >> > Somebody had run coax designed for balanced audio service from
>> >> > the stereo jack to the two contacts of the meter on the front
>> >> > pannel.
>> >> >
>> >> > This would be a good way to do the modification.
>> >> >
>> >> > Balanced-line audio coax has 3 conductors. There is the
>> >> > shield plus two center wires instead of 1. One would want to
>> >> > route it so that it is as far away from the high-power RF
>> >> > circuitry as possible so one doesn't induce RFI in to the
>> >> > tone oscillator or the meter, itself.
>> >> >
>> >> > It is likely that both sides of the meter are above
>> >> > ground, hince the balanced coax.
>> >> >
>> >> > Of course two runs of regular coax would also work.
>> >> >
>> >> > Martin McCormick WB5AGZ Stillwater, OK
>> >> > Systems Engineer
>> >> > OSU Information Technology Department Network Operations Group
>> >> > Walt Sebastian writes:
>> >> >> Hi Shaun,
>> >> >> It seems to me, back in the olden days when I had a Kenwood TS520,
>> >> >> I
>> > could
>> >> >> go about 50 to 60 KHz before I tuned up. I am sure other people
>> >> >> tuned
>> > up
>> >> >> sooner than that.
>> >> >>
>> >> >> Walt
>> >> >> WA4QXT
>> >> >> New London CT
>> >> >> [log in to unmask]
>> >> >>
>> >> >
>> >> >
>> >> > __________ NOD32 2956 (20080318) Information __________
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>> >> > http://www.eset.com
>> >> >
>> >> >
>> >> >
>> >>
>> >>
>> >>
>> >> --
>> >> No virus found in this incoming message.
>> >> Checked by AVG.
>> >> Version: 7.5.519 / Virus Database: 269.21.7/1332 - Release Date:
>> >> 3/17/2008
>> > 10:48 AM
>> >>
>> >>
>> >
>> >
>> >
>> >
>>
>>
>>
>> --
>> No virus found in this incoming message.
>> Checked by AVG.
>> Version: 7.5.519 / Virus Database: 269.21.7/1333 - Release Date:
>> 3/18/2008
> 8:10 AM
>>
>>
>
>
>
>
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