Portable WSPR Beacon Experiment

Greetings hams, Now that I’ve taken a long hiatus from HF, I think it’s time to get back to business. I built these little gems last night in hopes...

Greetings hams,

Now that I’ve taken a long hiatus from HF, I think it’s time to get back to business.

I built these little gems last night in hopes that I can get them to power my QRP labs transmitter.

They were easy enough to assemble, just apply the heatsink, and build the casing. I’m trying to step down my 12v power output from a linear power supply to 3.3v & 5v respectively powering the QRP labs transmitter & GPS device. I’m also understanding that they can be used to power Arduino type devices as well. I made sure to buy at least 2, since the reviews were a bit spotty on a few. You can find these online on Ebay for less than $3 without the plexiglass casing. I’m a bit on the clumsy side, so the casing will definitely serve it’s purpose. I’ve still yet to build the transmitter, that requires the better part of a day to assemble (for a noob like me anyways). Once I’ve verified that they’re working properly, I’m going to hook them up to my 9ah Bioenno battery:

 

(Speaking of Bioenno batteries, if you haven’t heard of them, look them up. Great company, and these aren’t the cheap Chinese knock off batteries either that you have to worry about exploding in your gear back if you go mobile. This battery has handled everything I’ve thrown at it from my 100w rigs, to my QRP projects)

Once I’ve got the QRP labs transmitter built, i’d like to package it all up, and suspend it under the tripod that I’ve been using to hold the F loop like so:

 

This way, I can take a portable WSPR package with me and test out different spots, perhaps some distant locations away from the city, or maybe on the beach to see how the salt water affects the signal, or better yet, the top of a mountain! I currently have the F Loop tuned for the 30m WSPR band: 10.138700. I was able to get the SWR down to 1:1 by adjusting the tuning loop while transmitting low power on CW. The loop is quite finicky when being adjusted! The loop would probably need to be checked/readjusted each time you took it out somewhere, but if you had an antenna analyzer or a portable hf rig, you could use that to help tune the loop. I plan on using the KX3, but I can’t imagine you’d have to move the knob much, if any at all when checking. Right now my Chameleon F Loop is sitting up in the attic listening to the 30m band, and for being where it’s at, I think it’s doing a pretty good job:

 

WSPR spots for K5ACL on a Chameleon F Loop (situated in attic) for 02/17/16-02/18/16

That’s one thing I appreciated about this loop was the fact that I was able to disassemble it and locate it up in my crawlspace, although I’m not sure how the antenna would fair up there long term in the heat. I’m unable to fit an MFJ loop up there because I can’t take it apart.

I’m sure that the HF signal is attenuated to a certain extent being in the attic, but I can already tell that just being up there, I’m getting much better results than I was just leaving it in my QTH. The loop is currently oriented in a North/South direction, after a few days i’ll switch it to E/W and compare the results. All this is allowing me to get better at using the loop, and testing everything out before I take this portable.

Edit: The SWR keeps fluctuating on the loop, I thought it would stay put, i’ll adjust it again a few times tonight, but if it keeps getting out of tune, this obviously won’t work, hence another reason a remotely tuned loop would work best for a situation like this.

Just another weird experiment.

Is it Friday yet?

73!

K5ACL

Categories
WSPR
No Comment
  • Mark Lunday
    16 July 2016 at 10:52 PM

    Be careful to NOT apply more than 5V to the QRP Labs kit. I have assembled one of these voltage devices, and once I build my new QRP Labs kit I will try it (fried the other kit with a voltage supply that had a spike).

  • Johnny Twist
    2 March 2016 at 5:49 PM

    Yay! Another Yahoo group to join! Thanks! There's a Yahoo group for everything these days!

  • Richard Burden
    2 March 2016 at 9:49 AM

    Have a look at the yahoo group WSPRBuilders. Fully built audio generator with GPS for time sync will be available shortly. Plans are well advanced for QRP transmitter kits to go with it.

    Regards

  • RELATED BY