Steve.
I tend to agree. With less current draw on 80 meters, I do not see
the problem with the pa.
I don't have a sweep generator so I will not mess with the bpf.
I will use the scope and see if there is lack of signal coming out of
the het osc and into and out of the bpf.
Sent from my iPhone
On Mar 17, 2009, at 8:04 AM, Steve Hunt <steve@karinya.net> wrote:
> Mike,
>
> At the risk of stating the obvious, the Argosy II fault would seem
> to be
> somewhere in the Tx chain that is unique to 80m. That doesn't leave
> a lot:
>
> Heterodyne Oscillator Xtal
> Bandpass filter
> PA LPF
>
> The PA LPF doesn't seem likely because you're not seeing much PA
> current. Can't be the Heterodyne Oscillator BPF because that is also
> used on 15m. Just possible the heterodyne oscillator transistor is
> faulty and doesn't like the "activity" of the 7.5 MHz 80m crystal.
>
> 73,
> Steve G3TXQ
>
>
>
> Mike Bryce wrote:
>> gang..
>>
>> while waiting on parts for the Omni B rebuild from Ten tec, I took
>> down another project or two from the racks
>>
>> I have a rather strange argosy I,
>>
>> for some reason, whom ever used this radio never liked cw..NO cw
>> audio
>> filter, but it has a 1.8 khz ssb filter
>>
>> the audio sounded really bad, and if you just tapped the case
>> anywhere, the cw would vibrate (?) hard to describe...
>>
>> anyway after working on this all evening, i found the problem..
>>
>> at one time or another someone had one of the pcb assemblies out. One
>> of the metal spacers that holds the pcb above the chassis had gotten
>> loose and rolled under the RF/Mixer pcb. the metal spacer would short
>> out a pcb trace and that's what caused the trouble.
>>
>> One down...
>>
>> The other project is a Argosy II.
>>
>> this one will produce RF power just fine except for the 80 meter
>> band,
>> I get very little, about 10 watts, yet on 40 and above there's 45
>> watts into a 50 ohm load.
>>
>> I've checked the band switch and everything seems in order. The PA
>> must be working as it producing power on the other bands. On TX on 40
>> I have 7ish amps from the power supply. On 80 meters I get see about
>> 3.5 amps.
>>
>> Any one ever seen this problem before?
>>
>> mike
>>
>> Mike, WB8VGE
>> SunLight Energy Systems
>> The Heathkit Shop
>> http://www.theheathkitshop.com/
>> J e e p
>> o|||||||o
>> Note: No trees were killed in the sending of this message, but a
>> large
>> number of electrons were terribly inconvenienced
>>
>>
>>
>>
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>>
>>
>>
>
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