Cheap digital readout for an old bird.

Discussion in '"Boat Anchor" & Classic Equipment' started by N3UIQ, Feb 1, 2020.

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  1. N3UIQ

    N3UIQ Premium Subscriber QRZ Page

    I recently received a 6 digit LED frequency counter module I ordered from China ($12 + $2 shipping). This thing is pretty amazing, I programmed it for an IF offset of 5.173 mHz, hooked the input to pin 8 of the plug in the accessory socket on my Swan 500 (VFO output) applied 12V to the module and now have a bright blue digital readout! I had my doubts as to how accurate this setup was going to bend listened in on some QSOs on 80 and 40 and it seems to be reading around 150 to 200Hz high and about 100 Hz high per the xtal calibrator not bad! I was also pleased to find that the drift was not even a factor after ten or so minutes of warmup. I now actually have a piece of 21st century tech in my shack, it was fun. Just thought I'd share that.
    K1LKP, N4FZ, W1BR and 2 others like this.
  2. N1OOQ

    N1OOQ Ham Member QRZ Page

  3. KE0ZU

    KE0ZU Ham Member QRZ Page

  4. N3UIQ

    N3UIQ Premium Subscriber QRZ Page

    Here's a couple of shots of the setup, I don't have the module in an enclosure yet, it's just on a breadboard taped to the radio just to make sure it all worked.
    I need to turn down the intensity a bit also and put a piece of tinted plastic in front of the LEDs for contrast.
    N4FZ and N1OOQ like this.
  5. W7UUU

    W7UUU Principal Moderator Lifetime Member 133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    Now you can always "be on the exact frequency" as so many hams seem to demand these days :rolleyes:

    Cool beans though - I love some of these little modules that are available these days

    K0UO and N7ANN like this.
  6. N3UIQ

    N3UIQ Premium Subscriber QRZ Page

    To be on "correct" frequency I have to turn the VFO to display 200Hx above the desired frequency because the carrier oscillator is running at 5.1728 mHz and the module's minimum increment for IF offset in 1 kHz, the manual rounds off the IF at 5.173 even though the xtal is 5.1728, I guess measurements to the hundreds of Hertz wasn't that easy 50 years ago and wasn't considered anything to worry about, but these days....!!!!. But yeah, maybe the frequency police won't beat me up as much. Yes there are very interesting new devices out now such as a palm sized network analyzer, a similar sized semiconductor analyzer hat even tells you the device number and the condition of the junctions, gain etc. For less than $100!
    KI4ZUQ, N4FZ and W7UUU like this.
  7. KE0ZU

    KE0ZU Ham Member QRZ Page

    I just bought some tinted tape from Hobby Lobby and put a piece on the display.

    Last edited: Feb 3, 2020
    WA1GXC and N1OOQ like this.
  8. WA5VGO

    WA5VGO Ham Member QRZ Page

    I have several of these and they are all adjustable to 100 cycles. If that isn’t close enough, there’s a tiny trimmer on the board that can be adjusted to get it dead on.

    KL7KN likes this.
  9. N3UIQ

    N3UIQ Premium Subscriber QRZ Page

    My module is a coupe of years old and the IF offset only goes out to three places, but I have a couple new ones on order that go out to 100Hz increments.
  10. W1BR

    W1BR Premium Subscriber QRZ Page

    Don't forget on CW most rigs will offset the display by 600 Hz or so; that is done to show the actual
    carrier frequency when receiving a 600 Hz beatnote, Otherwise you would have to zero beat the
    frequency. And other rigs offset the VFO for either USB or LSB, unless they have symmetrical
    sideband filters (one for SSB, one for LSB.) Just putting that out there for anyone who may not
    know the nuances involved when using these devices.

    Good enough unless you're gonna hug band edges, however.

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