[1000mp] Frequency Drift - ARGO measurement

[Tod - Minnesota]

A number of folks have asked about the ARGO frequency measuring software.
Here is the URL to the site which has the downloadable program:

http://www.weaksignals.com/argo

You will need to connect the FT1000 AF out port to the LINE IN port on a
sound card via a direct connection. No transformers are needed since you
will be receiving not transmitting.

To check your radio's frequency and stability do the following:

1. Manually enter 10.000.00 into VFO A. Be sure that you set the VFO so that
frequency is exactly 10.000000 MHZ down to the single HZ. Read your manual
if you do not already know how to tune to the exact cycle rather than the 10
Hz value shown on the display. Select an antenna that allows you to hear
WWV.

2. Set VFO B = VFO A.
3. Tune VFO A to 10.000.50 and select USB or LSB so that you hear the
carrier tone of 500 Hz. (I am traveling and forgot if it was USB or LSB that
will give the tone at 10.000.50 -- but one or the other will, probably LSB.)
4. Exchange VFO A and VFO B. Set VFO A to 09.999.50 on the dial and select
the Mode (probably USB) that allows you to hear the 500Hz carrier. Now you
will have one VFO that is reading 10.000.50 and the other reading 09.999.50
and each has a different SSB mode (LSB/USB).

5. Switch back and forth between VFO A and VFO B. If your ref oscillator is
set for the correct frequency the tone will be the SAME no matter which VFO
you are listening to. (If the tones are different, your reference oscillator
is not on the desired reference frequency.)

6. Start up the ARGO program and using the help screens set up the
parameters for your sound card. The Mode should be set at 3s dots and the
Speed should be normal. Click the Start Button in the lower right hand
corner and you will see a waterfall display. Look for a line at about 500 Hz
and click on the line. The trace will move horizontally across the screen
from right to left and the frequency will be shown at the top of the chart
and at the right side. When you switch from VFO A to VFO B the frequency
will change (unless you happen to be right on the reference frequency). Add
the frequencies shown for VFO A and VFO B together and divide the sum by
two. Subtract 500 from the result and you have a measure (in Hz) of how far
off of the correct reference frequency your radio is. (Note: If your radio
is 'right on' you will have added 500+500 to get 1000 and divided by 2 for a
result of 500. When you subtract five hundred from that you get zero which
is the error in the ref frequency).

7. Turn off the radio and stop the ARGO display (button at bottom right).
Let the radio cool for ten or 15 minutes. Turn on the ARGO display after
cooling the radio and the turn on the radio. You should be able to see the
reference frequency come back to the original value you measures. It may
take some time. Take readings and write them down. Make a couple of runs
this way to get a good idea of what the frequency error of your radio is. If
you make a reading every minute you can get an idea of the drift in Hz per
minute.

I will advise reflector readers when I have additional information on my web
site (probably at least a couple of days). If anyone does these measurements
and wants to share their results I would be interested simply to see what
the variability between radios happens to be. You can send results directly
to me or put them on the reflector == your call.

Tod, K�TO