[ARC5] BC659 dummy load

[Richard Knoppow]

    I said hot wire but meant thermocouple. They are somewhat similar 
but for RF I think the thermocouple type would have less reactance. 
Probably one can assume the antenna impedance was meant to be around 300 
ohms so the current would be something like 125  to 130 watts output. 
Somewhere, in some obscure not to say arcane publication is the spec for 
this meter.  I think my BC-375E, long in storage, has a thermocouple RF 
meter in the antenna circuit.

On 6/16/2016 10:06 PM, WA5CAB--- via ARC5 wrote:
> No.  I'm sure that at the time, and in the US Army, it would have been a
> thermocouple type, so much lower resistance than 300 ohms.  Thermocouple
> type RF milliammeters are not easy to come by today.  A 1 ohm resistor
> at the ground end of the 300 with a decent 'scope across it would work fine.
>
> In a message dated 06/16/2016 23:43:48 PM Central Daylight Time,
> 1oldlens1 at ix.netcom.com writes:
>>     Well, that tells you the load impedance is at least 300 ohms but not
>> the series resistance of the meter which would have to be added. I
>> presume they mean a hot wire meter. Is there any clue at all like a spec
>> on the meter type?
>>
>> On 6/16/2016 8:26 PM, WA5CAB--- via ARC5 wrote:
>> >The only place in any of the literature where I find the use of a dummy
>> >load mentioned is in TM 11-4023, page 26, paragraph 28.  It says that to
>> >check the transmitter output power, use a 300 ohm resistor in series
>> >with a 0-100 RF milliammeter.  Minimum reading on both channels should
>> >be 65 mA.
>> >
>> >Robert Downs - Houston
>> >wa5cab dot com (Web Store)
>> >MVPA 9480
>> >
>> >In a message dated 06/16/2016 17:12:51 PM Central Daylight Time,
>> >arc5 at mailman.qth.net writes:
>> >>Don't need the military one , but just what the resistance is supposed
>> >>to be. Anybody know?
>> >>
>> >>
>> >>Jim
>> >>Ac2EU
>
>
> Robert & Susan Downs - Houston
> wa5cab dot com (Web Store)
> MVPA 9480
>
>
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-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL