VK7RAE Beacon Frequency Test

[VK3HZ]

Thanks to a lot of hard work by Joe VK7JG, the VK7RAE 6m, 2m, 70cm and 23cm beacons near Devonport are now all GPS-Locked.

Nominally, the beacons are on xxx.474 MHz in each band. However, for "technical reasons", the 2m and 70 cm beacons are not exactly on their designated frequencies.

As an impromptu FMT (Frequency Measurement Test), and also to provide Joe with some feedback on coverage, I wonder if people could have a listen for the beacons and give their best estimate for its actual frequency (obviously this is a REAL challenge if you are, for example, in VK4 or VK6). The nearest to the actual frequency will have the honour of ... being the nearest to the frequency.

As a clue, they are within 10 Hz and, no, the frequency errors are not the same, nor is the 70cm beacon error = 3 x the 2m beacon error.

Regards,
Dave
VK3HZ

[VK7JG]

Thanks also must g

o to you David and Graham VK3XDK without your help it would not have been possible.

[VK3AUU]

VK7RAE 144.473995
I tossed up between that and 1 Hz lower, but this was the winner with two out of three answers.
On closer inspection it is definitely higher than 995 but less than 995.5 Probably 995.3. I can't get any closer than that.

David
VK3AUU

[VK5PJ]

okay, here is a shot in the dark, 1296.473.721 MHz from 971Km away.

another shot: 432.473.91 MHz

Have not tried to calibrate my sound card, so probably quite a bit of error.

Peter, vk5pj

[VK3OE]

Couldn't resist,,

Try 144.473.995.7,, now we ar arguing about 0.5Hz or so. Long key down makes it easier.

and 432.473.996.7, now this was a little more difficult because the 432 keying is fast enough to produce sidebands, so in the end a bit of a guess as to Hz.

Can't hear 1296 but will have a go at that as well when condx better.

Process used was with GPS locked signal generator on the nominal frequency and then measure the difference to the beacon frequency.
IC910 also GPS locked so it is stable, and seems to be very close to actual frequency, thanks David.

Andrew,
VK3OE

[VK3OE]

Well, can just see VK7RAE 1296 on spectrum lab @ 137mHz bandwidth.

How about 1296.473.995.2.

Andrew
VK3OE.

[VK3HZ]

Measurements to sub-Hz resolution should be possible.

[VK7JG]

Thanks for the reports all very interesting .
Andrew your measurements are about the same as mine .
I cannot measure the 1296 beacon as I do not have a rig.

The 1296 Beacon is a Kuhne 1296 GPS locked transverter driven by the 144.474 GPS locked beacon so the 2M error will be reflected on 1296 . I have no idea how accurate the transverter locking is. At least it will be on the same frequency every time you look for it .

If you have a separate 2M receiver where you can listen for the ID , the 1296 beacon will key at the same time .

The reason that the 432Mhz beacon is keyed for 0.6 seconds on then off for 2 seconds it so that the owner of the property can use their remote control to open their garage door . When we ran continuous carrier it killed the receiver .


Regards.
Joe VK7JG

[VK3OE]

Thanks David and Joe,

update,

144.473.995.26

I think my prevoius 432 and 1296 are pretty close.

Was fun to do the measurement, thanks.

regards,

Andrew
VK3OE

[VK7JG]

My readings this morning using FT847 and Spectrum Lab.
50.056999.64
144.473994.9
432.473996.6

[VK3HZ]

After hearing them all "loud and clear" over the last few days, I went to measure the frequencies today, and the bottom has fallen out of the propagation.
I can barely hear the 2m beacon and 70cm is very very faint on Spectrum Lab.

My best attempt at measurements:
2m - 432.473 995 403
70cm - 144.473 997 855

I'll post the actual frequencies (according to theory) in a couple of days.

Regards,
Dave
VK3HZ

[VK3HZ]

The theoretical frequencies for the VK7RAE beacons (according to the PLL divisor settings) are:

6m - 50.057 000 000
2m - 144.473 995 271
70cm - 432.473 997 028
23cm - 1296.473 995 271

Well done to all who had a go at measuring the frequency. All of you got more than close enough

Regards,
Dave
VK3HZ