Simple 14 MHz QRP PSK-31 Transceiver

Discussion in 'Amateur Radio News' started by G4TUT, Feb 3, 2008.

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  1. G4TUT

    G4TUT Ham Member QRZ Page

    Simple 14 MHz QRP PSK-31 Transceiver

    Steven KD1JV has published on his website an easy to build design for a 20 metre PSK-31 transceiver.

    The small lightweight rig is built with common, easy to get and inexpensive parts. Receive current is a modest 30 ma and transmit current averages 450 ma, with a peak output power of about 3.5 watts.

    KD1JV shows the transceiver with a PDA running Pocketdigi software.

    14 MHz QRP PSK-31 Transceiver

    PocketDigi 1.0.9 - digital modes for the Pocket PC

    Amateur Radio PSK31 Tutorial Videos on YouTube

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  2. N5WX

    N5WX XML Subscriber QRZ Page


    Very impressive and thorough. Perhaps someone could provide the boards.
  3. N4QA

    N4QA Ham Member QRZ Page

    Attaboy, Steve!

    I guess this novel design has answered that age-old question:

    "How come I gotta have a 'sideband rig' to do PSK?"

    It also reminds of:

    Bill, N4QA
  4. KC8PPD

    KC8PPD Ham Member QRZ Page

    Comparison to other qrp kits?

    It will be interesting to know how this compares to the "warbler" line from Dave Benson(?) Can anyone tell the benefit or drawback (aside from having to tune to 1kHz marker - maybe?) Would this design be more power efficient (having a class-c PA)?

    It is indeed an interesting concept, decoding the audio output from PC and using the information gathered to construct the PSK31 signal directly.
  5. K5CO

    K5CO Ham Member QRZ Page


    Very nice job; I will build one and see how I can do with it. By the way, my local parts stores have toroids packaged by Philmore. Here are their equivalent numbers and a man can buy them one at a time:
    T-37-6 is Philmore no. 86-1556
    T37-43 is Philmore no. 86-1563

    This circuit is the kind of thing we should get from our money in QST; but they never have anything so complete and they can't even spell "Printed Circuit",far less, publish one.

    Rob, K5CO
  6. K5CO

    K5CO Ham Member QRZ Page

    Someone said "maybe someone can provide the boards". I have been using Datak precoated boards and they can be exposed with a standard 100 watt light bulb and the developer is mixed with water (not that smelly xyelene stuff). It's fun to make your own board; a Dremel drill is almost mandatory.

    Rob, K5CO
  7. N9XCR

    N9XCR Ham Member QRZ Page

    That would be great to use here! I wouldn't mind building one for 40 and another for 20, but I'd really like to find a source for the boards as well. I gave up making my own boards long ago. It was fun trying, but it's just too much trouble.

    "This circuit is the kind of thing we should get from our money in QST; but they never have anything so complete and they can't even spell "Printed Circuit",far less, publish one."

    It requires somebody to submit the article and design to QST for it to be published. Know of anybody who has, and had their submission tossed aside?

  8. KB7ZTI

    KB7ZTI Ham Member QRZ Page

    Schematic and PCB don’t match up

    On the PCB at the top right corner where the Antenna jack is (J1) it shows it has a copper trace directly going to C24, but on the schematic it show it as
  9. N1YRK

    N1YRK Ham Member QRZ Page

    Nice, but

    It looks like a nice, simple design. Certainly inexpensive. Is anyone planning on kitting this design? I might take it up if no one else wants to. It could save more money, as components are cheaper in quantity. Specifically, there is those toroids with a minimum or of 25. At least, I could split up a large order among those who want the build the radio and not spend the money on extra toroids.

    I'd also like to see a 30 meter version.

    The need to tune a signal right into the 1000 hz on the software is annoying. I wonder if there's not some way to link the computer and radio to do this for us? Of course a PLL could do so, but that would add expense. I worry about the drift of an I&C VFO, but considering the rather short tuning range it won't probably be much of an issue (unless you are running MFSK16, perhaps). I wonder if there's some good "hardware hack" that we could put into the radio and software to change the frequency, without having a complexity and cost of the PSK-20 rigs (I really like the PSK series, but they are expensive). Maybe diode switching of capacitor banks? Or how about a stepper motor on the varicap ;)

    In any case, I'd like to get feedback from people who have built this radio and are operating with it. Particularly those using digital modes other than PSK31.

    Harvard Wireless Club...99 years old!
  10. VE9SY

    VE9SY Ham Member QRZ Page

    The biggest benefit I can see is that the warbler line except for the 80m version seems to be discontinued. I went to their site on Friday to order one and it's not there any more. It's listed on the site, but not on the order page. It states that if it's not there it is discontinued.

    Hopefully they will be brought back. I should have ordered one when I first looked at them, but we were looking at buying a house, and I didn't want to order it and then have to straighten out delivery problems after we moved!
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