I thought you all might be interested in this.
This response resulted from my specific question about my report, and
others, of a "S9+20", with the audio so loud that I yanked my headset
off". Sounds like I got an additional "boost" in signal strength from
an un-wanted "friend."
E. J. Kennedy wrote:
>
> Thanks for the additional information.
>
> First some background on the current facility status:
>
> Max power available at the current time is 360 kW. However, one transmitter
> cabinet has been removed from the site for repairs and one transmitter
> cabinet at the site is not being used because its associated antenna system
> has a problem that will be fixed next week. Thus the maximum power we have
> available is 320 kW and during this test, we used the full 320 kW on both
> of the frequencies.
>
> Here is the exact procedure used. All of the transmitter operation is
> automatic once the file is loaded and the start time is set. Each of the
> three tests consisted of a separate operating file. Each of the three files
> had to be loaded prior to its particular test.
>
> Upon loading the transmitter file, the computer waits until the planned
> start time. For the first transmission, this was 0429 UTC. At 0429 UTC,
> the transmitters are automatically brought slowly up to full power of 320
> kW. After about 20 seconds, the series of "V V V V V de haarp" was sent for
> one minute. Then a five minute carrier only transmission, then the CW
> message. The operating file had the actual CW message programmed to repeat
> twice. I, being a CW op, realized it was repeating half way through the
> second message transmission and alerted the control operator to stop the
> executing file. He did. The first message transmission therefore, had a bit
> of a repeat of the CW message. (People got a second chance to copy it or at
> least part of it)
>
> The second transmission on 6.99 MHz was to begin at 0440. When the file was
> loaded, the computer did not accept it. The file was re-loaded and the
> transmission began normally but slightly late. This time, I listened to the
> CW message at the end of the 5 minute carrier period and alerted the
> control operator at the exact end of the message. It stopped at the end
> this time. The third transmission at 3.3 MHz was identical except that it,
> too was a little late because of the delay encountered in loading the
> second file.
>
> I think this is consistent with your observations except for the sudden
> increase in signal strength of 20 dB or more. It is possible that a nearby
> (to you) frequency pirate or frequency policeman may have keyed up at that
> moment. It is possible that they keyed up within your receiver's IF
> passband but outside the audio passband. You wouldn't have heard it but the
> S meter would have seen the presence of a strong signal in the IF passband.
>
> You didn't say what type of station you have. KC6BXN in central California
> had access to a rhombic pointed at us. He was copying the 6.99 MHz signals
> at S9 +. KH6BZF in Hawaii with an ideal ham location looking out over the
> water directly at Alaska, received the 6.99 MHz at S9 +20. K6UR near Fresno
> received us at S9 +10 using a 3 Element 40 m beam at 95 feet. If you have a
> very good antenna system, I would not doubt that you received us at the S9
> level in California.
>
> Most of the hams East of the Mississippi heard nothing. I have a few
> reports of signals at S1 or S0 and parts of a Morse copy that makes me
> believe they really did hear us, but weakly. California and the Northwest
> states and the Northern midWest states had the best luck.
>
> As I'm sure you know, ionospheric propagation is fickle and unpredictable.
> It is for that very reason that we do research in this area. Since our
> power was maxed out at all times during this test, a sudden increase in
> signal level as you observed is of interest scientifically and physically
> if we can discount other explanations (like the possible one I gave above).
> I don't mean to discount your observation (That's what we were looking for
> after all!). I am eagerly awaiting other reports and I hope there will be
> many as detailed as yours.
>
> 73 from Alaska,
> Ed K3NS
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