Beacons

[VK2FLR]

I had an exchange with VK5PJ on the logger chat facility this morning about beacon modes.

Peter said:

VK5RBV on 144.456 is under test from Mt Kitchener (beacon site) modulation is WSJT - JT4D and limited CW. Antenna is a single omni loop on top of the tower.

I responded:

VK5PJ: I don't like the trend towards JT modes on beacons. The most detectable modulation on a weak signal is carrier only. Ask Rex! So the best thing for weak signal detection is steady carrier with minimal ident periods. Too frequent idents and VVVs etc just make weak carriers harder to see on waterfalls. For example I cannot detect VK1RSB because it does not run enough carrier. VK2RSF is fine because it does!

Peter responded:

VK2FLR: Michael, I dislike beacons that run long periods of carrier, so it would seem we each have different opinions.

I responded:

VK5PJ: Peter. That's OK. I spend 90% of my beacon listening time waiting for some AE on distant beacons. I have given up on the VK1 beacons because I do not see them now. But I used to when they ran carrier and minimal CW ID.

What do people think about this?

[VK2KRR]

My view on beacon modes currently is based on my observations of VK5RSE 70cm beacon and WSPR operations:

- JT4 is a nice novelty but soon wears off. I now feel its a waste of time.

- CW only I think is the best way to run a beacon. (Except if you can run it on WSPR)

- A serious network of beacons would run WSPR all on the same dial freq.

- Hard to please everyone.

[VK2WP]

I am quite happy with the way VK2RSY and VK2RSF are run. They are clear and easy to copy when conditions are reasonable.

I do not have a computer hooked up to my radio, so if I cannot hear it it is not there.

[VK5BC]

My view is it would be great if we could have our beacons running WSPR. With the number of VHF/UHF beacons in VK they could all easily fit into a 200Hz slot in our VHF/UHF band allocations. Big advantage is you only have to listen to one frequency and WSPR will decode signals lower in level than you can hear CW signals and you can still send a CW ID at end of each WSPR TX block. Only downside I can see is there may be heating problems with the 2min TX block but I guess you could have them TX every other 2min block. The other thing that can be an issue is frequency stability and timing but with GPS locking available these days I think these issues can be overcome.

I agree with Leigh and think the JT4D is probably a waste of time and straight carrier & CW ID is more value.

Anyway great to hear the Barossa beacons progressing and look forward to the reactivation of the 6m one along with future 70cm & 23cm beacons. Thanks for the efforts Peter (VK5PJ), well done.

73's Brian
VK5BC

[VK3PY]

VK5BC wrote: "With the number of VHF/UHF beacons in VK they could all easily fit into a 200Hz slot in our VHF/UHF band allocations."

Yes, they could, but how would you cope if such a beacon was installed near your QTH and happened to be within your antenna's beam width in a direction of interest? That's a serious issue in our patch of VK3, with the Mt. Anakie 2 & 70 beacons being pretty close to Geelong and Melbourne. Fortunately, they are very clean transmitters and they have directional beams pointing away from much of the local populations. There are those among us who would advocate spreading out the beacons over a much greater part of each band, well away from the weak-signal operating segments.

Also, something every beacon operator soon learns is that it's impossible to please everyone. Some people want keyed carrier. Others want CW and lots of it. Still others want as long a key-down period as possible. Then there's the digital mode brigade. Me, I'm just happy there are those who have the wherewithal to construct, install and maintain beacons.

Chas
VK3PY

[VK2KRR]

VK5BC wrote: "With the number of VHF/UHF beacons in VK they could all easily fit into a 200Hz slot in our VHF/UHF band allocations."
VK3PY Wrote : "Yes, they could, but how would you cope if such a beacon was installed near your QTH and happened to be within your antenna's beam width in a direction of interest?"

Hi Chas & Brian, If they ran as a true WSPR system, you would not have them TXing all the time for the reason Chas mentioned, you would never hear anything else if you were close, and if there was a good opening it could also cause problems. They would have to run like WSPR does randomly with a predefined time percentage or set up to TX once every 10 mins or predefined TX time. 
People looking for a constant carrier may not find this suitable.
If it was a predefined time frame, and people knew when to watch for it, say at the 10, 20, 30, 40, 50, 00 min, that could take some guess work out. WSPR also looks like a key down CW signal to the untrained eye and if there was the CW ID at the end it would help to ID.
But if sites were set up GPS locked Geelong could be on 144.490530 for example, and Mt Gambier could be on 144.490550. So with an accurate set up, you can basically identify which site the signal is coming from by its position on the waterfall the moment it begins transmitting. 
VK5VF would be on 144.490450, Toowoomba would be 144.490440, Perth 144.490460 etc. 
In amongst this home stations can contribute also with their own transmissions and automatic reception reports to the database.
People already running WSPR would then not only have signals from other home stations, but would be able to monitor and report signals coming from the established, well positioned beacon sites like 3RGL 5RSE 5VF etc, 24 hours a day. Where as currently, these beacons are more than likely transmitting CW etc to no one a large % of the time which is a waste. Where as with the WSPR method described they would be useful and reported 24 hours a day by those able to leave rigs monitoring etc. People can then look up the data from anywhere in the world and see whats happening. Sounds a lot more useful to me and a better use of resources.
The good thing about having them all on the one dial frequency is that when there is an opening, your monitoring all the beacons all the time. Not just one beacon on one individual freq. Particularly useful for E openings.

I doubt that anything like this would ever happen, but this is the way that I see that it could work. There could be other ways of doing it too.

This is probably not really what Mike VK2FLR was trying to get from his original post, but its an interesting discussion.

[VK2ZIW]

My use for Beacons is Antenna Testing both at home and on Field Days.

And for this use, a beacon that is always there is terrific. It would be a total
pain if I had to wait 15 mins for a 20 sec transmission.

The Dural beacons are my "life blood".

My 2c.

Alan VK2ZIW

[VK3RX]

straight carrier & CW ID is more value.

Agree, and carrier may or may not be continuous.

I don't bother with digital mode beacons.

Radios scan their memory channels, and PC may or may not be on or running any AR software.

[VK5PJ]

Hi,
The VK5RBV beacon on 144.456 MHz (under testing) has had a small tweak to its ID scheme, it is now running 60 seconds of CW ID including grid locator and carrier then a cycle of JT65B, with some CW to fill in the last 10 seconds of the period. At present it is running about 8w to a single PAR OmniAngle loop at around the 12 mark on the tower.

There is also a QRP beacon on 50.456 running CW and JT65A, this is the replacement for the 50.315 beacon we took off the air when the FT8 digital mode exploded. It will get a P.A later in July/ August and be back to being 15W, same HALO antenna as before.

Once I can find a reasonable OMNI for 432 and 1296 those beacons will also be turned on.

Reports are most welcome to: vk8zlx @ gmail dot com

Regards,
Peter, vk5pj

[VK2KRR]

Hi Peter, I think its reasonably good the way you have it set up there now, im just having a listen to 144.456 now.
For 8 Watts to an omni its quite audible here.

[VK2FLR]

Thanks for the information Peter. Everyone should be happy now. At least I am! If the CW transmissions are on the JT sync frequency then the whole cycle will be viewable on JT65. All will be viewable on a waterfall.

[VK2KRR]

Hi Mike,
They are both on same freq, JT65 sync tone is probably 300 Hz lower than where the CW shows up. I will get a screen capture of what it looks like later.

[ZL3RC]

Ive been interested in WSPR beacons for a while now and as Im currently upgrading ZL3SIX and ZL3TEN is has come up again over here too.

Living close to a strong WSPR beacon could be problematic but with a random TX period this may not be as big a problem as we think.
I think the ability to listen to one freq. and hear all the beacons that you have propagation to is a greater benefit. Even if you get RX blocking for a random 2 min period.

My approach to this was to have the best of both worlds, sort of, in that you only TX WSPR for 2 mins so what do you do with the rest of the time? Go back to the designated beacon freq. and run a carrier with CW ID or what ever you want. Those that don't have digital capability or what to listen as they have for years to a CW beacon on its own freq. you can do so except it will QSY for a random 2 mins.

Such a beacon is easily realised using the cheap and small QRP-Labs TX module, ZL3TEN uses one of these as an exciter and it makes for and very compact and versatile beacon. This unit has the ability to move Freq and mode via a very easy two button programming operation and its output could be used to replace the current freq. determining circuit.

I can't think of anything more useful than a network of WSPR beacons here in ZL and VK. Well I can a network of small cheap WSPR RX stations all reporting back to WSPRnet.org. And this cheap WSPR RX may be just around the corner. Have a look at https://www.zachtek.com/product-page/2pcs-wspr-receiver I believe Harry has a 6m version in testing so one of these and a Rasberry Pi running WSPR could well be the answer.

As a beacon operator you quickly realise how much cost there is in running these dam things and here again running WSPR for 2 mins every 10 mins or so would be a huge power saving.

Just my thoughts...

Roger ZL3RC
RE66

[VK2KRR]

Roger,

Thats exciting information and the best idea I've heard of regarding a frequency shifting beacon controller. I'll be interested to hear if you get the idea up an running.

I've also spoken to Harry from Zachtek regarding the receivers, he advised me that he is working on a built in pre-amp for the 6m and 2m units. I plan on getting the 6 and 2m versions to put in the work car, particularly over summer could be interesting.

[ZL3RC]

Thanks Leigh,
Well as a proof of concept Im going to setup ZL3TEN to do the freq. jumping operation but Ill have to use my call sign on the WSPR channel as we don't currently have a licence for the freq. I think I can do that, have to check, if not it will have to wait till we get some paperwork done!

Be interesting to see what spots it generates.

I think the 6m and 2m recivers Harry is producing will be very useful and hopefully get some more WSPR RX stations reporting on the web site.
Gee I never thought of mobile operation. Do you intend to send reports back to the web sit while mobile, what I cool idea if you are.

Roger ZL3RC
RE66

[VK2KRR]

Hi Roger,

Certainly cant wait to hear the WSPR incorporated beacon results.

Yes, plan was to be able to monitor WSPR on 6m 2m while mobile and/or stationary mobile. I usually have a laptop PC in car with a 3G/4G mobile internet connection, so was planning on feeding reports back to the database. The issue would be reported grid square from the mobile, will have to be manually entered. I guess so long as the first 4 digits are correct, the 5th and 6th digit will be close. At least if propagation comes through it will give some indication. 
Was looking at a vertical omni for 6m which should be OK for Summer Es. and try sort out a horizontal omni for 2m band, Es and tropo.
Be interesting to also compare signals between home station and somewhere out mobile, and also monitor TX signals from the home station at different locations on the road.

[VK2ZIW]

Hi Leigh and Roger,

As Standard Licensees cannot use 50.0 to 51.999 MHz, Should we put a Codec2 mode 700D repeater on 6m somewhere?

I've modified David Rowe's freebeacon code to "repeat" - HOWZAT. It's running on 7177KHz now and expects a text string
of my callsign to trigger a repeat, "parrot" fashion. Running on a Pi, a Banana Pi at 25% CPU usage (one core).

Car antenna for 6m. A 2m 5/8 is pretty close and is OK on receive.

[OZ2M]

Hello list

I just found this list, so sorry for the late response. The topic of what should a beacon do is identical to what was discussed nine years ago in the group behind OZ7IGY that wanted to upgrade the beacons with digital modulation and referenced locked among other things.

However, before we started to design the new beacons we made a member and user survey as well as presenting the conceptual idea(s) on a handful of VUSHF meetings. This was done to collect the needs and ideas because the OZ7IGY beacons are made for the users not for the designers and builders. No one expressed any wishes for a non-continuously transmitting beacons – in fact quite the opposite. VUSHF propagation conditions can be short lived and thus not detected if the beacon signal is not present all the time. Furthermore, if the beacon signal is randomly on the air using the beacon for propagation studies and rig alignment becomes cumbersome if not impossible.

The concluding requirements to OZ7IGY were:

- The beacon should be readable without a computer. Therefore, a beacon should not be 100% digital (machine generated modulation - MGM) but either 100% analog or mixed mode

- The beacon, at least the analog part, must be readable even when the path is distorted i.e. by rain scatter, aurora etc. Who says we have finished detecting new propagation techniques? So the beacon must also be "forward compatible"

- The analog part of the identification must be frequent both to identify the beacon but also to "handle" QSB

- Today most beacons identify themselves every 30-45 seconds. But waiting for the identification "always" seems to long

- The analog identification should be readable by "all of us" not just the very high speed CW operators. Thus 12 WPM/60 LPM as already specified seems to make sense

- It should be possible to calibrate to the beacon. Thus a carrier is needed to zero-beat on. Today this is specified to be about 20-30 seconds

- When using the beacon for signal strength measurements, antenna pattern, receiver aligning etc., it is important that the envelope of the transmitted signal remains the same during the entire sequence

- For a mixed mode beacon the MGM should act as a "pre-human condition" detection, i.e. better than -10 S/N as well as automated monitoring. A very good CW operator can detect signals way down in the noise perhaps -10 dB S/N. But "all of us" may only go down to say -3 dB S/N

- Must fit into the current 1 kHz beacon to beacon spacing structure

- Low phase noise in order not to disturb nearby stations

- The MGM must be transmittable via a class C amplifier. Overall power consumption is a concern. OZ7IGY has 12 beacons on the air and uses 800 W DC continuously. The electricity bill is close to 4000 AUD annually and energy prices will continue to go up. For the same reason a group is busy with a renewable enerIGY project

But it is also worth noting that some users asked for:
- more carrier, less carrier, no carrier
- no MGM, only CW
- more power, less power
- EME training beacon

There is no one-size fits all. Likewise when it comes to the MGM. There are no free lunches when it comes to sensitivity, speed, robustness and flexibility. So the requirements were a good and robust general purpose sequence with equal offset tuning for all parts of the sequence AND just like any other CW beacon.

If I am to advice anyone on beacons it would be:
- what is the purpose of the beacon?
- who are the users? FM-stations, analog DXers, mixed mode DXers or digital DXers?
- what do the users/listeners  want?
- don’t start backwards by looking at the S/W available – if any

[OZ2M]

For those who are interested here is a link to my presentation on the subject "PI4 the Digital mode for Beacons
and why is it a success" made at the recent RSGB Convention: http://rudius.net/oz2m/ngnb/pres_rsgb_co...2m_pi4.pdf

[VK4AQJ]

The advantages of a WSPR beacon outweigh any disadvantages (and I can't think of any). If you can just see the signal on the waterfall, you can decode the signal. I've been monitoring the VK4RBC beacon on 137.44kHz and receive it at a S/N of -05 at 400km even during the day . When I finally get transmit capability on 2200m, I will be able to check if my signal is received and at what strength, and yes, it has CW ident every 2 minutes. The lowest signal I have received WSPR beacons was at -33 dB.

WSPR beacons like that are very useful for testing the effectiveness of your antenna system, and you can use them without a computer if you want.