QRSS beacon completed and transmitting

I finished putting together G0UPL’s QRSS beacon transmitter today and it seems to be working fine. Tomorrow I’ll have to dig up a 6V wall wart to power it but for now am using 4 AAA batteries just to make sure it’s putting out a signal with my callsign embedded.

With those batteries, it puts out a maximum of 150 mW which I’ll back down to 100 mW once I start putting it on the air. Initial tests show it doing what it’s supposed to do based on the display presented by antenna-less K3 feeding its received audio into Argo. Freq measurement of 10.140.048 is read with my MFJ-259 – not sure how much faith I should put into that gadget as a freq counter. Probably not much but we’ll see.


It’s not housed yet but will be going into a clear-top tin from the 4S-QRP Group (which has been looking for a worthy tenant).


Well that didn’t take long & it appears the freq counter function of the MFJ is quite accurate after all. Here’s my presentation at 0130Z as received by W4HBK in Pensacola FL. I’m not sure why the key down representation is inverted (above) as received here at my QTH but not when received elsewhere:

With a solid presence at 100 mW, I dialed the power down to 40 mW. Not sure if the shift upward in freq is due to me making the adjustment or the fact that less internal heat is generated within the transmitter’s components at the lower power. I suspect the latter since the drift occurs slowly over several minutes:


BTW, this is QRSS6 (6-second dots).

The next morning as received by KL1X/5:




  4 comments for “QRSS beacon completed and transmitting

  1. August 11, 2010 at 9:26 pm

    Good evening John,
    Nice to see that things are up and working. Keep us updated with reports. I too am not sure why key down representation is inverted either. Good to know about the MFJ-259 accuracy I have one as well.

  2. August 11, 2010 at 11:13 pm

    Thanks Mike – well that was interesting. My first time on a new mode and with such a simple & inexpensive little kit. I’ve pulled the switch and am now QRT for the night.

    Nice video on your website…

  3. August 13, 2010 at 7:47 am

    Hi John,
    I hope all is well with you and yours. I’m very happy you are enjoying the kit! If you leave it running and look at some of the European grabbers, you should from time to time see your signal pop up over here in Europe.
    The mystery of the inverted signal on your own local reception might most probably be due to having your receiver set up on the wrong sideband, would that be the case?
    Vy 73 de Hans G0UPL

  4. August 13, 2010 at 9:22 am

    Thanks Hans – I very well may have to change sidebands when using my rig for that purpose. I wonder how long that would have taken to occur to me if you hadn’t mentioned it…!

    The kit seems to run for hours on AAA batteries so I may leave it at that – the 6v wall wart that I found actually puts out 7.4 volts unloaded, and as far as its concerned, the beacon transmitter doesn’t offer enough of a load to bring it down to its labeled 6 volts.

    73 & TNX de AE5X

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