[Lowfer] Using Argo

[Eric Smith]

Thanks for the help, Stan!  Good info .. just what I needed to know.

Yes, the G0MRF preamp is quite tight.  I've used it at 2200m before
and it is tuned right where it needs to be ...

It works great, too.  I wish I had another and I'd keep that one tuned
to 185.3 ....

I'll be listening at 2200m tonight.

73,
Eric KD5UWL


On Dec 3, 2012, at 1:08 PM, "Stan, W1LE" <stanw1le at verizon.net> wrote:

> On 12/3/2012 12:51 PM, Eric Smith wrote:
>> Please remind me ... it has been a while but I now finally have my
>> radios going after moving again:
>>
>> If I have my R-75 tuned right on a specific beacon's frequency, then
>> that signal will appear in Argo at the frequency of my side tone,
>> correct?
>
> Correct. The Beat Frequency Oscillator (BFO)or the sidetone is the offset at audio frequencies.
> The side tone may be different for other radios,, eg ICOM IC-703+ has a 800 Hz side tone in CW demodulation.
> Other radios have a 600 Hz sidetone.
> The resulting audio may change with USB or LSB demodulation or a CW reverse or the regular CW demodulation.
>>
>> So if sidetone is 700 Hz, then in this scenario the beacon would
>> appear at 700 on the waterfall display, right?
>
> Right, plus or minus the local oscillator accuracies
>>
>> Also, it seems like the last time I got this working I had to use the
>> Reverse feature (CW-R) but I can't remember why.
> A perculiarity of the radio. Their design engineer's choice. Some radios allow a change with a menu.
>
> For accurate calibrations I use a HP 3336B signal generator with an external GPS/DO reference at 10 MHz.
> For ARGO ( a great program ! ) I calibrate the soundcard first, injecting a audio tone at 1000.00 Hz
> or any other known accurate freq you have.
> Then I connect the radio audio output to the soundcard and inject the RF freq I am listening to.
> For example: if I am listening to an RF of 137.000 KHz and my RX has a sidetone of 800 Hz in CW reverse,
> then I would expect to see the test signal at 800 Hz in ARGO. Then calibrate out the minor differences due to your radio's
> LO accuracy.
>
> As I recall the G0MRF preamp has a tight bandwidth. Is it tuned to where you want it ?
>
> Stan, W1LE    Cape Cod   FN41sr
>
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