Beacons

[W3WN]

In view of a recent comment in Decon about a lack of amateur radio threads here on an amateur radio forum...

My club has sponsored a 10 meter beacon in the US Virgin Islands, NP2SH/B 28.275 MHz, for a good many years now. Don't bother listening for it right now, it's all dead... about the only thing you can do with that transmitter is go through it's clothes and look for loose change.

A club member, Mike N3BSQ, has offered to resurrect the beacon, either by repairing the existing unit or building a new one.

The original beacon transmitter was a Uniden 2600, followed up by a RadShack HTX 100. Or was it the other way around? Anyway, the drive on both was lowered to about 1 Watt, but time still took it's toll.

Any suggestions on Version 3?

I should mention that Mike just put a 10 meter beacon on from his home, N3BSQ/B on 28.2535 MHz. He's using the "Little Joe" transmitter kit that was featured in QST back in 1981. (You can find it in QRP Classics and Solid State Design) Cost for the unit is about $20 plus crystal. My concern is that, well, if something goes wrong with Mike's unit, it's right there in his house to fix. But NP2SH/b is a bit further away, and even though Paul NP2JF is kind enough to host it, we can't ask or expect him to fix it if it breaks.

Steve W3SRL, who built the original beacon and it's replacement, is up to his eyeballs in school, work and home, so we're trying not to burden him with this. That said, he is taking time to look for an old commercial unit (VHF LOW ex-public safety I'd presume) that we can adapt. Same problems, though, plus if it's an older unit, we have to figure out how to safely ship it... and so forth.

Any technical suggestions appreciated!

Keep in mind that I'm just the conductor (since I'm club president this year and most likely next as well), Mike N3BSQ will be the actual head of the project...

73, ron w3wn

[KC2UGV]

How about this kit: http://qrp.kd4ab.org/2000/001030/0001.html

[W3WN]

That's a parts list, but it doesn't say much about the kit itself.

[KC2UGV]

That's a parts list, but it doesn't say much about the kit itself.

It's the Iowa QRP-10 (That's what I know of it). Can't seem to find anything except this:

http://www.norcalqrp.org/files/K8IQYIowaQRP10.pdf
http://www.norcalqrp.org/files/K8IQYIowaQRP10Sch.pdf

Hope it helps :)

[ab1ga]

A couple of questions:
Am I right in assuming it's a CW beacon?
You're satisfied with 1 Watt or so output?
Is there a price limit?

Although you said you can't expect your host to fix the beacon, would he be able to just replace the whole thing and mail you the dead one? That way you could keep shelf spares at the site, and fix them at your leisure without downtime.

This could be a nice homebrew project rather than just a kit.
The Parallax propeller chip has an on-chip programmable oscillator that will go that high, and is programmable in a high-level language called Spin. It can delivered a keyed carrier, which would need filtering and squaring, which could then drive a Class E amplifier.

[N8YX]

Convert a mobile AM-only CB rig.

Use one with an MB8718, 8734 or PLL02A PLL chip. A re-crystal and realignment is usually all that's necessary.

Then reduce its power to 1w. A small ball-bearing fan blowing on the rear of the case will provide adequate cooling.

A BASIC Stamp would make an ideal keyer for this project. If you really want to get crafty, there are a couple Ethernet adapter boards available for use with a Stamp, Rabbit and similar microcontrollers. These utilize Java code to provide a web interface. One can use transmitted commands to manage devices behind the front end; you could remotely control the transmitter (or check on its operating parameters) from your browser.

[W3WN]

A couple of questions:
Am I right in assuming it's a CW beacon?
You're satisfied with 1 Watt or so output?
Is there a price limit?

Although you said you can't expect your host to fix the beacon, would he be able to just replace the whole thing and mail you the dead one? That way you could keep shelf spares at the site, and fix them at your leisure without downtime.

This could be a nice homebrew project rather than just a kit.
The Parallax propeller chip has an on-chip programmable oscillator that will go that high, and is programmable in a high-level language called Spin. It can delivered a keyed carrier, which would need filtering and squaring, which could then drive a Class E amplifier.
To answer the questions in order:

Yes, it's a CW beacon. (Has to be on that part of the band)

I don't know the technical reasons why 1 Watt output was chosen; that may be the nature of the beacon network itself, I will have to find out. Certainly QRP power level.

Price limit? Well, the club is a little flush in cash right now, but we're not about to spend a couple of thousand on a custom made unit... reasonable costs are acceptable.

Actually, if we can find something reasonable, I am in favor of having an "off the shelf" backup available. Since we're talking about the US Virgin Islands, postage back & forth will be reasonable. Delivery times will be an issue... overnights under most circumstances won't be practical, but down time of a few days is acceptable. What the heck, it's already been QRT for a few months now.

But first priority is to get the system back on the air.

[W3WN]

Convert a mobile AM-only CB rig.

Use one with an MB8718, 8734 or PLL02A PLL chip. A re-crystal and realignment is usually all that's necessary.

Then reduce its power to 1w. A small ball-bearing fan blowing on the rear of the case will provide adequate cooling.

A BASIC Stamp would make an ideal keyer for this project. If you really want to get crafty, there are a couple Ethernet adapter boards available for use with a Stamp, Rabbit and similar microcontrollers. These utilize Java code to provide a web interface. One can use transmitted commands to manage devices behind the front end; you could remotely control the transmitter (or check on its operating parameters) from your browser.

That will be up to the ad-hoc committee working on the project. Considering the two rigs already smoked, I wonder if another conversion project is worth it.

Now if this was my project, and I could get my hands on a working crystal controlled CB from the 23 channel era, I might consider this the way to go.

As far as the controller... I understand the existing one is functional. Again, I'm going to defer to the committee on this, and there are some nice things out there. But remote controlling via the web? Not an option, not unless NP2JF lets us know that they have full internet access available on St. John.

Again, first things first. Since the first two units smoked after several years in service (each), Phase 3 is to get something back on.

[N8YX]

The original beacon transmitter was a Uniden 2600, followed up by a RadShack HTX 100. Or was it the other way around? Anyway, the drive on both was lowered to about 1 Watt, but time still took it's toll.


Considering the two rigs already smoked, I wonder if another conversion project is worth it.
I would start by doing a root-cause failure analysis. Something's just not right at the transmitter site.

When I had node BARBER on the air, one of its radio ports used an HR2510 and an HR2600, alternatively. These were set up on 28.195 and ran 1200 baud. The antenna was a 3-el yagi, fixed towards the southwest. AZSE was the node at the other end of the "pipe". When Sporadic E or just plain ol' F-layer skip set up and the path opened, my 10M port saw as much as 16 hours use per day running an output power of ~20w on LSB. Day in, day out...all summer long...year long...I had that setup on the air from late 1993 until the fall of 2005 and it never once missed a beat.

Both of those rigs are still hanging 'round the shack - I had them mobile for a couple years until I sold the truck in which they were mounted.

When run with a low (< 1.7:1) SWR, you practically cannot kill them. Both of mine still work great.

Identify the cause of the failure before placing another transmitter in service.

[KC2UGV]

That will be up to the ad-hoc committee working on the project. Considering the two rigs already smoked, I wonder if another conversion project is worth it.

Now if this was my project, and I could get my hands on a working crystal controlled CB from the 23 channel era, I might consider this the way to go.

As far as the controller... I understand the existing one is functional. Again, I'm going to defer to the committee on this, and there are some nice things out there. But remote controlling via the web? Not an option, not unless NP2JF lets us know that they have full internet access available on St. John.

Again, first things first. Since the first two units smoked after several years in service (each), Phase 3 is to get something back on.

I can send you one (A 23-channel crystal CB). I've not used it, since there have been some mods applied (And, I'm not really deft enough to figure out what they were).

[W3WN]

< snip > Identify the cause of the failure before placing another transmitter in service.

Oh, no argument there, and I agree completely.

Keep in mind the location of the beacon... on St. Johns USVI. High up on the hill, but still in the tropics. There are weather effects (including but not limited to corrosion issues, just ask the various DX'ers with Carribbean stations) to deal with that aren't a problem up here.

If it's simply an antenna issue, we'll get another antenna. I've had a lot of success with my Solarcon A-99, we can get a new one off eBay for not too much and send it down there, for one thing.

Beyond that, I'd be speculating.

I've discussed the matter with N3BSQ, and Mike has the delegated authority to make the final decisions. About the only thing he can't do on the project is personally travel to the USVI to install it -- well, not on the club's dime, at least. (Unless I get to go too!)

[KA5PIU]

Hello.

When I was playing with a beacon it put out a stair step signal at 28.385 MHz.
This was 10 mW, 100 mW and 1 W.
This is an old Motorola Business Dispatcher 2-way that I got cheap a few years ago.
The radio is rated at 50+ watts FM and so can be set up at this power level and transmit forever.
If you could hear all 3 levels you had a strong signal, just one and it was weak, nothing all that subjective about it.
This was an active beacon, you had to transmit a 150 Hz tone to trigger it at a later point.
This has a tube final.
I did this while I was also converting another to do 6 and 2 meters, dual band.
It want silent when the employer all but banned ham radio for me on or near the job.

P.S, ID power level was 10 watts.

[KG4CGC]

I was going to suggest a Ramsey kit but they've just about abandoned the Amateur market. They offer a 20m QRP transmitter that one might engineer to 10m. 45 bucks seems a waste though considering the flea market and ebay finds.

[KA5PIU]

Hello.

I would go with an older Commercial radio.
Get a low band low side split, something rated at least 25 watts and would prefer more.
A 25 watt rated transmitter running 1 watt will not be harmed if transmitting into an open or short for days on end.
And commercial equipment is easy to find and cheap.
To do a stair step signal you simply use a quad output logic device and 3 power transistors each connected to a pot and diode.
This is in series with the power out adjust with 4 transistors in parallel.
Sequencing the thing will give you the 3 power levels.
For the ID power level you have another transistor and pot, diode, triggered by the IDer.
4 transistors total, one logic level is not connected, this is the zero output start of the stair step signal.
Again, if run within ratings, and this transmitter will, it will run for years trouble free.
I replaced the crystal oscillator board in the Business Dispatcher with TCXO units from an old MT-500 talkie, smaller and more stable.
This means that the transmitter is within 12 Hz at all times!
CB radios are a consumer item, intended for light use and built to a price point.

[W3WN]

I was going to suggest a Ramsey kit but they've just about abandoned the Amateur market. They offer a 20m QRP transmitter that one might engineer to 10m. 45 bucks seems a waste though considering the flea market and ebay finds.

That would explain the relative flood of Ramsey kits on eBay.

[W3WN]

Hello.

I would go with an older Commercial radio.
Get a low band low side split, something rated at least 25 watts and would prefer more.
A 25 watt rated transmitter running 1 watt will not be harmed if transmitting into an open or short for days on end.
And commercial equipment is easy to find and cheap.
To do a stair step signal you simply use a quad output logic device and 3 power transistors each connected to a pot and diode.
This is in series with the power out adjust with 4 transistors in parallel.
Sequencing the thing will give you the 3 power levels.
For the ID power level you have another transistor and pot, diode, triggered by the IDer.
4 transistors total, one logic level is not connected, this is the zero output start of the stair step signal.
Again, if run within ratings, and this transmitter will, it will run for years trouble free.
I replaced the crystal oscillator board in the Business Dispatcher with TCXO units from an old MT-500 talkie, smaller and more stable.
This means that the transmitter is within 12 Hz at all times!
CB radios are a consumer item, intended for light use and built to a price point.
Cowthief,

Steve W3SRL works for the Fire Department in his municipality. As I said in the original post, getting our hands on a working VHF-Low unit should not be a problem, there are still plenty of those in the area.

The State of PA is learning the hard way that 800 MHz trunked systems don't work that well amongst the hills and valley of our local terrain. Nevertheless, the state is still pushing the counties and municipalities to abandon VHF for UHF, so the equipment is coming on the market.

[W3WN]

Update

Just got an email from Mike N3BSQ. The remains are being sent back to him, and from what I gather, the existing antenna has sucumbed to the sea air and should be replaced as well.

Personally, I've taken a liking to the Solarcon A-99; I have one here that was given to me, and for a vertical, it performs pretty well on 10 - 17. My thinking is to go ahead and pick one up off of the usual suspects and send it down to the USVI, pending the OK from the host.

[W2NAP]

i have to say the weather down there is hard on it all. a 2510 at 1W should last for years

[W3WN]

i have to say the weather down there is hard on it all. a 2510 at 1W should last for years

I tend to agree. But I'm not onsite, and the original beacon & the current one were both assembled and installed prior to my current tenure as club president, so I don't know all the particulars.

[W2NAP]

yea its not easy to cause going to the site would require a bit of cash.

[W3WN]

yea its not easy to cause going to the site would require a bit of cash.
Are you kidding? If I went to the USVI without my wife, there would be hell to pay once I came home.

I learned that lesson a few years ago the hard way. I was supposed to go on the last NP2SH trip, and she through a fit that I was going without her. It was easier to back out (and swallow the $400 for my share of the rental) and skip the trip, than to face the repercussions... and never mind that she wouldn't have been able to go anyway, she didn't want to hear it.

[KG4CGC]

That would explain the relative flood of Ramsey kits on eBay.
Yeah. Anyone want to buy a built FM stereo transmitter and separate 1W amp?

[kf0rt]

I got one of those Ramsey kits once; the analog one that cost about $40. Dunno what it put out, but it couldn't have been as much as a watt. Very unstable, too -- couldn't keep it on freq.

[KA5PIU]

Hello.

Fired up the old beacon 'transponder', the thing works.
When I first got it I replaced all of the electrolytic capacitors and checked everything else, this was a radio I got real cheap with a bunch of other stuff.
When I finished it was in nearly perfect shape, refinished with automobile paint, the whole bit.
I retuned it for 26.620 MHz and used it until VHF AM replaced this band, that was later replaced by VHF FM.
The mate to it was given the same treatment but was high side low band and I cut the power to under 1 watt to comply with part 15, at 49.83, 49.86, 49.89, and at 49.85 MARS.
Since I could run full power at 49.85 I came up with the selectable power level thing, based on some VHF marine radio circuits.
Since the radio was only 2 channel I removed the selector switch and replaced it with a 2 wafer rotary selector, 12 X 2 channels.
The channel elements as well as the oscillator board came from a circle M talkie.
I did this as the Business Dispatcher was offered in both AM and FM and thus a dual mode was very easy to do.
But, this radio was designed to provide years of reliable service, the only weak area for this series of radios was the oven heated crystals and oscillator circuits, something I simply replaced.
But, 20+ years in taxicab service, and they were taken out of service to go to a new band? that says it all.
Commercial equipment is just so much better than Amateur that look at that as my first choice.

[W3WN]

Cowthief! Klaatu barada niktu!

[ab1ga]

Cowthief! Klaatu barada niktu!

Shop smart, shop S-Mart!

:-)

[NQ6U]

I want a beacon, lettuce and tomato sandwich now.

[KG4CGC]

I want a beacon, lettuce and tomato sandwich now.
http://i25.photobucket.com/albums/c79/bebop5/3198121516_164fb94f11.jpg


I found this on the table in the food court. Split it?

[NQ6U]

I found this on the table in the food court. Split it?

Sure, thanks! And I have the perfect wine to go with it, too:

http://www.greenwoodlakewines.com/labels/P11831.jpg

[KA5PIU]

Hello.

It is a tossup.
http://www.bumwine.com/md2020.html
And,
http://www.bumwine.com/tbird.html

[NQ6U]

Hello.

It is a tossup.

No, sorry Rudy, it's not. I put together a spread sheet from the data available on bumwine.com, awarding 5 points for a first-place finish and down to one point for a fifth-place finish. The chart below shows that Thunderbird wins hands down.

What's the word?

http://i815.photobucket.com/albums/zz79/gyrogeerloose/wine_graff.gif

[W3WN]

Time for an update...

N3BSQ has been working diligently on the new NP2SH beacon the last few weeks. Some delays due to an illness (his, he's better now) and some other mishagauss... but NP2SH/B returned to 28.275 MHz last night, from Mike's home. 2 W out, nice signal heard around the area.

That's the good news.

It's down right now.

The bad news, well, it had a little chirp to it. Mike was trying to track down why. I'm now pretty sure it was related to the power supply... which exploded on him last night. As he put it to me on the phone, "it let the blue smoke out. Blue smoke stinks!"

Mike is trying to get a hold of one of the club's best troubleshooters, Frank N3FB (who is the Chief Engineer at WPXI TV). Replacing the power supply isn't a problem, he has others. We just want to make sure that when the supply went, it didn't take some transistors with it.

On the bright side, if this had to happen, at least it happened up here, not once it arrived in St. Johns!