Beacon Project "Common and Precious III" (OFF air, 26510 kHz, 8W)

[Zazzle]

Hi everyone,

So, as a HF addict I need my next drug shoot aka "HF project" . It's going to be a beacon again.

I felt for doing some urban exploring lately which made me visit an old industrial complex not that far away from home. The are several smaller towers on the areal and two big chimneys. I did some climbing. WOA! That would be the perfect location for a Beacon Transmitter. I mean... 80m above the ground and no big city close by. F#ck, yes!

The smaller towers are easy to climb on. The plattform offers many option for installing Antennas. The tower itself is about 50 meters
The chimney is... a challenge to climb on. Exhausting. Getting stuff up there is even more of a challenge. But, my god, what an awesome place for a Beacon. Sadly, there's a metal tube comming from the chimney which is even longer than the platform and may interfer with possible Antennas. Also, it's too risky I think.

So, for reasons of security, accessibility for maintenance and an obstacle free Antenna environment I will go for the smaller tower. The only bad side is: other people might be tempted to climb on it. Less than on the chimney.

I need your opinions now, because I've a hard time making a decision. It's about possible signal propagation and use of Antennas.

Frequency 1 - 10M Band
Pros

• I have an old 5/8λ CB beam at home. It's easy to install and it's also relatively broadbanded. Therefore, the SWR should be not an issue.
• I could also use a 1/2λ inverted V. Each side would be about 2,60m. That's managable.

Cons

• The propagation isn't the best and DX connections are rare.
• There's not really much activity when it comes to pirate radio/beacons.

Frequency 2 - 40M Band
Pros

• Awesome propagaion, also during daytime.
• Many pirate activities just below the offical HAM-Bands

Cons

• A huge antenna is needed. A Dipole is not an option.  I think I could build a KGD. But this sort of antenna has a very small bandwith and the SWR matching is tricy because it's sensitive to the objects around.

I think a good working Antenna in combination with less potential contacts is still better than a bad Antenna with more possible contacts?

Your opinion?

Greetings,
~Zazzle

[Zazzle]

Mornin',

Made my mind. I'm going with the version on 40m. I'm curious about the KGD Antenna. So, jep, gonna build that one

Kind regards,
~Zazzle

[Zazzle]

Hi there!

It has begun. After working on the circuit every now and then I placed the parts order yesterday. During the next couple of weeks I'm going to build the Transmitter unit and Antenna.

I did a lot of rethinking. A decision that took extremly long was about the final Band/Frequency. Despite my previous opinion, I settled on the 10m Band now. Instead of just going by theory only I did some Band monitoring almost every day. Despite the fact, that the propagation for long jumps is overall quite bad on 10M, it comes with a lot of advantages: when the Band is open, pretty neat jumps can be archived. It's quite quite. Not a lot of noise, so even a small signal stands out against the noise floor.

Another argument that made me settle on 10m was the Antenna size. I still want to install the whole system (Solar powered this time) on the industrial chimey (shown on the picture in my previous post). I expect a LOT of heavy wind up there and therefore mechanical stress.

Actually, I'm still not sure about the Antenna. Two types are already out of question:

• I have a CB Antenna "Hurricane" flying around. After reading reviews I better throw it away.
• A friend has an 5/8λ Vertical from his CB-Age. But I doubt that this long monster will even survive the first storm up there.

Let's discuss that in a different topic.

So far, those are the features/ideas

• Approx 1,3W.
• Solar powered by an 50W solar module. Wayyy overdone during summer time but likey still not powerful enough during winter time.
• Uses 3 seperate 1.300mAh Ni-Mh Battery packs in parallel. In case one Battery pack fails the system won't die.
• Water proof IP67 heavy duty Plastic housing, holding the charger unit, Battery pack and TX-Unit.

Kind regards,
~Zazzle

[Zazzle]

Hey

Progress! I've etched the PCB and populated it almost entirely (most inductors are still missining). In fact I'd build two identical boards. One for the final setup and one for experiments (so I don't ruin the primary board like I almost did with the 30m one.).

Also, I wanted to play a bit with a Frequency Doubler Circuit. Just becasue I haven't for a while. The Frequency I'm gonna use is 27.215,00kHz (so I use a 13.605,5kHz X-tal) , which is basically CH #21 on the CB Band. Due to the Signal propagation behaviour I won't molest many people. Ch #21 is devasted around here. Haben't heard anyone on it during the last 3 weeks. Also, chances are good that it may be heard because it's a knows used/frequency.

From the left to the right: Oscillator, Frequency Doubler (and Buffer), PA Stage and Filter. The PO will be around 1.1W. One Vari-Cap is to pull the X-Tal and the second tunes the Inductor for the Frequency Doubler into resonance.

[skeezix]

How did you etch the board?  Looks pretty good.

[uhf35]

From the left to the right: Oscillator, Frequency Doubler (and Buffer), PA Stage and Filter. The PO will be around 1.1W. One Vari-Cap is to pull the X-Tal and the second tunes the Inductor for the Frequency Doubler into resonance.

How did you etch the board?  Looks pretty good.

I would like to know it also

[Zazzle]

Hey skeezix!

How did you etch the board?  Looks pretty good.

It was done the old fasioned way by using a photo active PCB material and Ferric Chloride Etchant.

The layout was done in Eagly Professional by hand. Since I didn't want to do a through-hole board but a SMD-like surface mounted one (easier for debugging and testing). I put the components from the library into their final position and started routing the conducting paths by hand  (with the "draw rectangle" function).

I'm not satified with the job. The board  turned out too dense (I'm used building high density PCBs and the big screen fooled me). It's a big ugly to solder and I hope I won't end up with oscillation due to too little component spacing.)

But: thanks a lot!

Greetings,
~Zazzle

[BoomboxDX]

The best reception I've had with 10 meters is late afternoons / early evenings, usually during fall and spring.

I also had good results with a single quad loop antenna on a short pole only ten-fifteen feet off the ground. It worked amazingly well on 11 meter SSB, also received 10 meters and VHF low band very well.

So don't rule that out as a backup for the antenna you're mounting on the pole.

Probably wouldn't work on a high tower because a quad loop is sort of like a kite when in the wind.

[BoomboxDX]

^^^^^^^
I think I either put this reply into the wrong thread by accident, or it sort of was shifted.

It was intended for another thread about 10 meter propagation and 10 meter antennas.

Sorry for the confusion.
Boombox

[Zazzle]

Hey,

heh, I was already wondering about it. No worries.

~Zazzle.

[Zazzle]

So!

Progress. A little. Mostly theory.

I made my mind and likely won't put up the solar powered beacon soon. There's just no use in hurrying things and face problems later. I had several problems with the H/W of the 30m beacon. The second will be ~35km away from home and on a huge tower. I have no desire to go up and down again and again.

I've build two trnsmitter boards in advance. One for debugging and one for operation. That leaves me with the opportunity to get one on air while having the second device for debugging at home.

So! I made my mind and came to teh conclusion that I'm going to install the 10m test beacon on the same roof as the 30m one. Since I have grid up there I'm also gonna add a 5W PA (which I happen to have flying around ;p).

I think at the end of the month I have it on air. Now I'm still left with the question about it's name. I ponder about such like "The Ugly", "Wild and Free". Open for suggestions!

~Zazzle

[Njmikec]

Funny how this hobby, in your case and maybe others', has crossed roads a bit with Urban Exploration - something I have dabbled in from time to time.  Fun stuff.  Do no harm, take pictures, leave only footprints. 

Meantime, I tried to pick up the 30m beacon last night on my R-5000 with no luck but I live in a radio-noisy area between New York and Philadelphia.  I also have some noise reduction work to do around the house.

I look forward to hearing your 30m signal at some point and wish you luck on your 10m adventure.

Mike

[Zazzle]

Heyho!

Had a look at the project yesterday and started working on it again. Found a mistake I made in the circuit note - and of course I've build the circuit that way. Let's see whether fixing it brings the project on track again.

Also, I made my mind about the tower thingie. No Tower. To far away and to annoying in case I've to fix stuff. I'm going to install the project on the old air field close by (which is a nature park so no one will run over the area which means it's pretty safe from being damaged by idiots).

Also, I'm gonna make this one finally all Solar powered. A friend of mine gave me several 12V/7Ah Lead Acid Batteries whichcome with at least 60% of remaining capacity. I'm gonna glue and connect them in parallel. Nice batter ypack for fee. Also, I got a broken (front glass) 240W PV panel that still outputs ~150W.

I've calculated that I need about 2,7Ah per day. Works fine with a 150W panel. Also during winter.

Since I'm gonna use the 10M Band I could also stpp broadcasting during night.

Anyway, I keep you updated.

~Zazzle

[Josh]

Zaz, if it's going to be on a tower, is there any way you could shunt feed the tower itself as your antenna?

[Zazzle]

Hey Josh!

Zaz, if it's going to be on a tower, is there any way you could shunt feed the tower itself as your antenna?

I decided against. Too far away. It's always a 60km trip when I want to try something. Also, for 10m there's a lot of small and effective antennas. Hell, even a dipole is small and can be done with stable steel rods.

But I had ideas about shunt feed the tower before. Once, I had some half-drunk discussion with a friend and we were joking about feeding that tower on the 80m band with 100W.

There's a sketch we did back then (see it attached).

But after I read literature about I had serious doubts. Literature says that impedance matching is tricky.

What's your experience with that? I'm quite interested in this kind of antenna.

Kind greetings,
Zazzle