VK5RBV to come back at Full steam

[VK5PJ]

Hello,
I am happy to report that today I have received and paid the invoice from the ACMA for the updates to the VK5RBV beacon allocations on 50 MHz and approval for the addition of 144, 432 and 1296.

At present the 144.456 MHz beacon is on at a 10 watt power level to a single 'PAR omni angle' antenna (Horizontal Omni) at the 12 Metre level on the club tower modulation is CW and JT65B on alternate minutes, reports are welcomed.

50.456 is running as only the exciter (100 mW) into a single HALO at the 6 Metre level on the tower, Modulation is CW and JT65A on alternate minutes. I hope to have it up to the expected 10 Watt level in the coming weeks.

432.456 as yet does not have an antenna installed at the site but I have some omni horizontal antennas at home that can be pressed into service.

1296.456 is ready to go but the antenna is still a mystery as to what to use.. it might end up with a number of small yagis in Key directions (will need to source a splitter).

All of these beacons are part of a ZL2BKC beacon controller and can run a number of modulation schemes

[VK7HH]

Excellent work Peter!

I will definitely make use of the beacons this summer. Thanks for the hard work.

Regards
Hayden

[VK2AAE]

5RBV was the first VK 6m beacon I heard. Very pleased it's back and THANK YOU very much
pat r

[VK4CZ]

Thanks Peter - great news. Will keep an ear out when next near shack.

[VK5PJ]

Hello, as of today at 23:00Z all of the VK5RBV beacons are off, I am working on integrating the 50 MHz PA and hope to have it back on air in the next few days.

[VK5PJ]

Feb 2019 update.

50 MHz beacon is on-air doing heat soak tests from my home QTH (5 KM from beacon site). getting the 50 MHz section going has taken a lot of my time and energy but hope to have it at the propper site over the weekend of 9 - 10 of Feb. This will see 50.456 and 144.456 on air with 15 watts 24/7

Code: Select all

Modulation:
 50.456 MHz, 1 min of CW ID and 1 min of JT65-a
144.456 MHz, 1 min of CW ID and 1 min of JT65-b

[VK7HH]

Thanks Peter.
Is the 2m beacon on air yet, or still under test?
I've been listening but haven't heard it during openings.

Hayden

[VK5PJ]

Feb 10th update

50.456 MHz (15W) and 144.456 MHz (12W) were turned on at the Mt Kitchener site today. The 144 beacon was on previously in 2018 but had been off since Nov 2018 to allow me to add the P.A for 50.456.

Peter.

[VK5PJ]

Hmmph, looks like the P.A on 50.456 has failed, signal is back to exciter levels here at home... 144.456 is going all okay so unsure what has happened.

[VK5PJ]

Well, it has been a while,
found the Mitsubishi module on 50.456 was dead, not a board fault Hmmph.
Went looking of a replacement module, nope, no longer available. A new version is advertised out in Google land but only people with stock seem to be China and I am not willing to take that gamble. (Minikits list it as coming).

I put a please help on VKClassified web site to secure at least one Philips FM-828 E-Band radio so I could convert the P.A for use on the 50.456 beacon and ended up with three, thanks to the kindness of a ham in VK3 and a local here in VK5.

Using the information listed here:http://www.unixservice.com.au/hamradio/ ... m828e.html the P.A was first tested before conversion, then moved to 50 MHz. The exciter and receiver boards were stripped out and the relay in the P.A removed. complete wiring loom removed and just the needed point to point wiring was put in

At this point, from around +8dBm input (what the ZLPLL gives me) I can easily create 15W on 50MHz, now just need to visit the beacon site and connect it all up. (27-Oct-2019)

[VK6XLR]

Hi Pete,

Nice work!

For info, the Simoco SRM9000 E0 uses the Mitsubishi RA30H0608M module. However they want a damn fortune for them. Last quote was $90 + GST and $20 postage
So if you can find a E0 somewhere

[VK5PJ]

Thanks for the tip SKI, have not run across many PRM80's from low band.

VK5RBV, 50.456 MHz, 1 min CW 1 min JT65A, about 12 W into the original HALO antenna, 27th Oct 2019. Sounds OK at home and 5BC said it was strong at his place..

VK5RBV, 144.456 MHz, 1 min CW 1 min JT65B, about 15 W into single a PAR OmniAnge, antenna (Horizontal polarization), checked power and fixed GPS antenna as the time sync was bad.


Any reports welcomed to: vk8zlx at gmail.com

[VK2AZ]

Good work Peter,
I have updated VKSpotter.com

And added the 2m Beacon.
Let me know if any of the details need to be changed.

[OZ2M]

Hi

I can't say why the RA30H0608M died. But I can think of two reasons, yet there may be many more.

Second Harmonic
One reason could be the level of the second harmonic that is only about -5 dBc. If the power module is followed by a low pass filter, which is highly recommended, the power returned to the module may kill it over time. For normal QSO use the duration of the returned power may not be critical, but, perhaps it is for beacon use. EI0SIX has been using a RA30H0608M on 6 m for some years now but only at 20% duty cycle.

But here is more about the second harmonic issue using the RA30H0608M on 6 m: https://groups.io/g/RFzero/topic/output ... n/38958219

The level of the second harmonic, out of the RA30H0608M, is why we decide not to use it for the OZ7IGY 6 m beacon. But on 4 m it has been running flawlessly for almost seven years now. So has the power modules on 2 m and 70 cm. More about OZ7IGY here: http://www.oz7igy.dk/

Bimetallic effect
A second reason may be the bimetallic effect on non RoHS compliant modules. This effect was seen some 15 years ago. See the very end of this page: http://rudius.net/oz2m/70mhz/pmpa_kitdocs.htm

You may check the bias track in any case.

Bo, OZ2M

[VK6XLR]

..... Philips FM-828 E-Band radio so I could convert the P.A for use on the 50.456 beacon .....

Using the information listed here:http://www.unixservice.com.au/hamradio/ ... m828e.html the P.A was first tested before conversion, then moved to 50 MHz. The exciter and receiver boards were stripped out and the relay in the P.A removed. complete wiring loom removed and just the needed point to point wiring was put in

At this point, from around +8dBm input (what the ZLPLL gives me) I can easily create 15W on 50MHz, now just need to visit the beacon site and connect it all up. (27-Oct-2019)

Seems VK6RPH has failed as well. I think both modules came from the same batch and supplier.

When modifying the FM828e PA, how did you account for the keying envelope shaping that was part of the ZL2BKC PA module PCB?

[VK5PJ]

Hi Ski,
I did not try to add the keying cct from the ZL2BKC board as I was in a major hurry to get it on air before our trip to Egypt (now back from 2 weeks away).

It had occurred to me afterwards that the pre-driver on the P.A board is supplied from a separate 10 volt reg supply (controlled by R7 on the Audio / Control board in the 828), which could be keyed in a similar way to the ZL2 P.A design and maybe shaped in a similar way. this would make the FM828 P.A a good fit for these beacons should the 144 MHz P.A fail at some point.

Just a thought... the 828 P.A did not need any extra stages and is driven straight from the ZLPLL and I use the variable R7 on the control board to set my desired output power.

[VK6XLR]

Hi Pete,
Thanks, I'll investigate further. I was looking at using just the 828 PA module. No other 828 board. Seems simple enough as 2 x RF, Vcc & Vcontrol connections.
I gather then your PA is on all the time, without keying?

[VK5PJ]

Yes SKI,
P.A is on in class C all the time, I kept the Audio/ control board in there but cut the traces going to the Audio Amp and the other regulator so they can not mysteriously cause a fault. Also removed the change over relay in the P.A and put a wire link in its place.

By doing this I keep the variable voltage for the first stage of the P.A and can easily set my overall gain to hit my target output power via RV7 on that board (just like they explain in the 828 manual)

Maybe not the best solution but the beacon is ON-AIR after a long absence and I can mod a second P.A here in slow time to get the trimmers in mid range and experiment with keying the 1st stage voltage too... left it all in the 828 case but removed all the wiring harness and just did point to point wires to get only the bits I wanted alive..