2m WSPR Ref Locked Stations

[VK4BLK]

It might be a good idea if Ref. locked stns. could indicate in their logger profiles that they are locked and on what bands

[VK2KRR]

Need another box to write those details in.

[VK3ZAZ]

Check this out who needs power


2014-12-22 06:14 VK3ZAZ 144.490512 -23 0 QF12ag +30 1.000 VK2KRR QF34mr 524 326
2014-12-22 05:36 VK3ZAZ 144.490513 -21 0 QF12ag +30 1.000 VK2KRR QF34mr 524 326
2014-12-22 05:20 VK3ZAZ 144.490514 -22 -1 QF12ag +30 1.000 VK2KRR QF34mr 524 326
2014-12-22 05:04 VK3ZAZ 144.490515 -22 0 QF12ag +30 1.000 VK2KRR QF34mr 524 326
2014-12-22 04:42 VK3ZAZ 144.490505 -16 0 QF12ag +30 1.000 VK2KRR QF34mr 524 326

17 db drop 16 db drop in snr

2014-12-22 04:38 VK3ZAZ 144.490504 +0 0 QF12ag +47 50.119 VK2KRR QF34mr 524 326

[VK3ZTE]

It's a good point, but from my observations, it might be more complicated than we would think. It appears to that some 'GPS-locked' stations are soft-locked in that the GPS provides a pacemaker function to the frequency source inside the transceiver box whereas others are hard locked in that the GPS-derived signal totally replaces a deactivated internal source. Hence, some stations that are 'GPS-locked' still bounce around frequency wise in the seconds after going from rx to tx whilst others come on bang on frequency and stay there for the whole 2mins. The difference is very evident to anyone who spends much time looking at the various received traces. Then, incidentally, there is a further group (possibly of just one) like me whose tx and rx chains are totally independent so that what goes on in one has no effect whatsoever on the other. Hoping this isn't too provocative. cheers 73 Grant S.

[VK2KRR]

Hey Steve, how about these -->

2013-12-17 01:04 VK3XPT 144.490523 -27 0 QF22nd 0.02 VK6DZ OF84ux 2464 km
2013-12-17 00:58 VK3XPT 144.490527 -27 -1 QF22nd 0.05 VK6DZ OF84ux 2464 km
2013-12-17 00:50 VK3XPT 144.490531 -26 0 QF22nd 0.1 VK6DZ OF84ux 2464 km
2013-12-16 23:54 VK3XPT 144.490516 -26 1 QF22nd 0.2 VK6DZ OF84ux 2464 km
2013-12-16 23:34 VK3XPT 144.490474 -28 1 QF22nd 0.5 VK6DZ OF84ux 2464 km
2013-12-16 22:40 VK3XPT 144.490526 -25 0 QF22nd 1 VK6DZ OF84ux 2464 km
2013-12-16 22:20 VK3XPT 144.490539 -23 0 QF22nd 2 VK6DZ OF84ux 2464 km

Thats 20mW, 50mW, 100mW, 200mW, 500mW, 1W, 2W.



Taken from the first post of this thread http://www.vklogger.com/forum/viewtopic ... 29&t=12013

[VK3HZ]

Grant,

You might be confusing Time Locking and Frequency Locking.

Time Locking is done by periodically adjusting the PC clock to match a time reference. It may be done every minute, 5-minutes, 30-minutes ... depending on how accurate you want to be. In between, the PC clock may drift slightly, but would generally not affect the transmission apart from slightly shifted timing.

Frequency Locking has the Reference Oscillator within the radio constantly locked using a PLL to an external source like a GPSDO. The radio will always be on frequency.

Those people you see that move around in frequency when Tx starts - probably due to thermal effects - would not be Frequency Locked.

Regards,
Dave
VK3HZ

[VK3ZTE]

G'day there Dave

No, hopefully I'm not confusing frequency locking with time locking, the latter clearly being a whole separate subject and I acknowledge lack of timing accuracy also cause issues - albeit slightly less obvious ones.

Back on frequency locking: there are stations around that are ostensibly frequency locked that nevertheless shift around quite a bit - I sometimes see 10Hz or even more within 10 secs or so following switch over - so I can only assume that in going from tx to rx or vice versa, they are losing lock from their external source be it GPS, rubidium, caesium beam or whatever. I certainly take your point about thermal effects but wonder too if power supply effects are causing mischief. It seems to take excessive time for the PLL(s) to settle back into equilibrium. My guess is that most of these radios were never designed to operated continuously with frequency precision of 1 or 2 Hz over seconds let alone minutes while switching between maximum output (say 50w continuous pulling say 15amps) and several hundred milliamps . Perhaps the provision for external clock input is just a not very well developed afterthought? The thing is, that if the accurate and hopefully clean, external source were to totally supplant the internal source, then there wouldn't be a problem but I get the impression that few work that way?

Of course, the other possibility is as you imply, that many of these stations are not really frequency locked at all but who knows?

[VK3HZ]

Is there a particular radio brand/model in question?

As part of the XRef stuff, people regularly ask "Can my rig (brand/model) be locked?" I've done quite a lot of wading through Service Manuals and I'd have to say that all brand-name amateur transceivers made within the last 10 years or so derive all their internal frequencies from one reference oscillator. So, if that Reference Oscillator is locked with a PLL, or an external Reference substituted, there can be no frequency movement. As well, the frequency generation chains remain on all the time - the frequencies are simply fed to different mixers between Rx and Tx.

Modern radios can provide high precision frequency. As an example, an FT-817 was fitted with an XRef-FT (a locked Reference Oscillator substitute) and the frequency measured on 1.5 MHz. The frequency was within 0.01 and 0.05 Hz of the dial frequency, purely because of the limited resolution of the DDS used in the FT-817 VFO. With the dial set on one frequency, there was no detectable variation in frequency.

Of course, the accuracy is only as good as the external 10 MHz reference being used. An OCXO, Rubidium or GPSDO should be very good. However, there are some who use a TCXO and that would generally not give a good result - possibly what you are seeing.

Regards,
Dave
VK3HZ

[ADMIN]

Hi all

2m WSPR operators might like to check out the new functionality in VK Logger.

New fields for 2m WSPR have been added.

click for full-size

More details have been posted here.

[VK2KRR]

Here is the current list and what freq they are set to TX on -

Jayson VK1JA - 144.490.570 (GPS)
Leigh VK2KRR - 144.490.560 (GPS)
Jeff VK5GF - 144.490.530 (GPS)
Andy VK5LA - 144.490.515 (Rubidium)
Keith VK5AKM - 144.490.500 (GPS)
Wayne VK2XN - 144.490.500 (GPS)
Derek VK6DZ - 144.490.485 (GPS)
Scott VK4CZ - 144.490.470 (GPS)
Phil VK5AKK - 144.490.470 (OCXO)
Peter VK5PJ - 144.490.460 (GPS)
Dean VK3NFI - 144.490.450 (GPS)

[VK5KK]

BTW: Confirming VK5AKM now uses a GPSDO as per http://www.ebay.com/itm/121530825744?_t ... EBIDX%3AIT

Cheers

David VK5KK

[VK5PJ]

Hi David,
could you comment on how clean the 10MHz out is? There appears to be a nice OXCO in there, so I would hope it is good.

BTW: Confirming VK5AKM now uses a GPSDO as per http://www.ebay.com/itm/121530825744?_t ... EBIDX%3AIT
Cheers
David VK5KK

looking for some thing affordable for locking some new beacons..

Regards,
Peter, vk5pj

[VK5KK]

Hi Peter

Quite clean sine wave output and suitable as a microwave reference. Uses a Neo 6M GPS, as best I can work out its internal DDS runs at 10 MHz and compared with the OCXO. The oscillator is trained and often stabilises before the oven would be fully warmed (watching current). Two versions, square wave and sine wave out. The OCXO is recycled double oven type, no GPS antenna connected it settles close to frequency each time ( 0.1Hz)

Cheers

David VK5KK

[VK3ZAZ]

Here is the current list and what freq they are set to TX on -

Jayson VK1JA - 144.490.570 (GPS)
Leigh VK2KRR - 144.490.560 (GPS)
Jeff VK5GF - 144.490.530 (GPS)
Andy VK5LA - 144.490.515 (Rubidium)
Keith VK5AKM - 144.490.500 (GPS)
Wayne VK2XN - 144.490.500 (GPS)
Derek VK6DZ - 144.490.485 (GPS)
Scott VK4CZ - 144.490.470 (GPS)
Phil VK5AKK - 144.490.470 (OCXO)
Peter VK5PJ - 144.490.460 (GPS)
Dean VK3NFI - 144.490.450 (GPS)

Yeah someone had a go at me other day
I already have GPS dingle for time locking...
Going a bit over the top are we not?
My box with the $200 rip off tcxo is all I intend to provide
Looking at the Mt Burr rubidium or this Trimble GPS thingie worth about $5K which I cant seem to even get to look at a satellite
think I will pass thanks, a rack mounted box just to hold a 821 on channel PASS
anything more for 2 metres is a pedantic overkill