Simple QRSS transmitter

Discussion in 'Homebrew and Kit Projects' started by SA7CNG, May 10, 2018.

ad: L-HROutlet
ad: l-rl
ad: Subscribe
ad: l-assoc
ad: l-BCInc
ad: Left-3
ad: Left-2
ad: MessiPaoloni-1
ad: L-MFJ
  1. W4KJG

    W4KJG Subscriber QRZ Page

    Wow! Tack SA7CNG.

    In all my QRP and weak signal fun, I have somehow been elluded from QRSS. It reminds me of the late 1960/1970s experiment known as the U.S. Navy Proiect Sanguine.

    I plan to trying QRSS out as soon as I can.

    Ken
     
  2. SA7CNG

    SA7CNG Ham Member QRZ Page

    Working on QRP/QRSS equipment without an Oscilloscope wasnt that easy, so i went out and got one. Siglent SDS 1052DL+ 50MHz was the cheapes digital oscilloscope i could find at my lokal electronics dealer, but it works like a charm.

    Having used only analog oscilloscopes in school for many years ago wasnt a problem, menus are rather intuitive and there a lots of smart functions.

    [​IMG]

    [​IMG]
     
  3. N1OOQ

    N1OOQ Ham Member QRZ Page

    The RBN reports it as "12 wpm"...?
     
  4. SA7CNG

    SA7CNG Ham Member QRZ Page

    That is correct, its 12 WMP. I have been unable to find any QRSS frequency crystals, the supplier linked to earlier in the thread was non responsive. I have tried to adjust a 10MHz crystal to 10.140MHz but i have only managed to move the frequency about 40-50Hz from the crystal resonans frequency with capacitors.

    In order to test out the QRSS transmitter i need to transmitt on a frequency that the QRSS grabbers listen to, and post images of the waterfall on. By speeding the whole thing up to 12 wpm i was able to see my transmitter on reverse beacon.
     
  5. N1OOQ

    N1OOQ Ham Member QRZ Page

    Ah, ok. I wonder if RBN would even recognize 0.5 wpm or whatever you guys use?

    The standard approximate maximum for "pulling" a crystal is 0.1%. At 10 MHz = 10 kHz. There are other options, but they are not simple.
     
  6. SA7CNG

    SA7CNG Ham Member QRZ Page

    I made a new smaller circuit, and a suiting encolsure from some scrap metal i had lying around. In its newest form it sends CQ with QRSS 3(3s long dots), with about 400mW of output power, on 7,028MHz. I will put it on the shelf untill a QRSS crystal is found.


    [​IMG]
    [​IMG]
     
  7. KK4CUL

    KK4CUL Ham Member QRZ Page

    This whole project is really fascinating! It's making me want to start breadboarding again. Great work.
     
  8. KV4PD

    KV4PD Ham Member QRZ Page

    I have a question: Where do you get those little round solder pads?
     
  9. VE3CGA

    VE3CGA Ham Member QRZ Page

    I've got tthe same question.
    Are they punched out from double sided board with a paper punch? possibly drilled out with a hollow "tubing" drill??

    Got a bunch of double sided board, and lately everything with micros has been on single sided
    home brew the way you have shown gives me some use for doing something rf with the extra double sided boards

    project looks good
     

Share This Page