Re: GB3MCB on 23 cms


HI Dave,

I can't see your screen shot for some reason :-(

However I aim for a 1KHz tone to within a few Hz on Spectran (audio card is calibrated), then I note the rig freq on USB and add 1KHz to it.

Currently the rig is tuned to 1296.845306MHz so I reckon MCB is currently on 1296,846306MHz give or take a few Hz.

I can measure the 1Hz shifts in freq from the IC-9100 on my freq counter and Spectran.

When I inject a signal from my sig gen set to 1296.846306 I get a 1KHz tone back.

Everything in the shack is locked to GPS, so pretty sure about the freqs.

MCB is even stronger this evening now it's starting to cool down a little, a good consistent s5.

73 Tim G4WIM / KT6UK

--- In, "Dave" <dave@...> wrote:

Interesting trace Tim,

I can detect GB3MCB and, at the moment, can even hear the CW ident. I'm also seeing doppler shifted signals from Aircraft reflections.

Attached (I hope) is a screenshot taken using SpectrumLabs a few moments ago.

As you will see, some direct and some scattered/doppler signals.

However, the thing I wanted to ask about is the frequency you mentioned. Is that dial frequency, or the frequency of the actual recieved signal? I see that your trace is at about 1kHz in, so I guess that you are using USB to received the signal? In which case, did you add the 1kHz audio offset to the dial reading?

Personally, I tend to monitor using CW with a 600Hz CW offset on the receiver and set the received signal to the 600Hz point on the waterfall. The dial frequency at the moment is 1296.847.38MHz and I often see that I need to add about 1kHz to what other people put out as the frequency that they hear the beacon on to what I need to use in CW mode.

Dave (G0DJA)

----- Original Message -----
Sent: Sunday, July 14, 2013 8:29 AM
Subject: [ukmicrowaves] Re: GB3MCB on 23 cms [1 Attachment]

Just as another data point I can hear GB3MCB up here in IO83LR at sea level.

It is peaking to s3 this morning and quite audible.

I make it's freq 1296.846325MHz - GPS locked IC-9100 and using Spectran to measure audio tone.
See attached file.

Using a 16 ele at about 30 feet AGL /ASL

As for 6 mtrs - MCB also seems a little off freq there as well, not sure why as my IC-7800 is also GPS locked, maybe they use a master reference ?

73 Tim G4WIM / KT6UK

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