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JT65a anyone???

Discussion in 'Working Different Modes' started by KD4MOJ, Jan 26, 2011.

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  1. KT1F

    KT1F Ham Member QRZ Page

    I think JT65-HF is a constant amplitude (unlike PSK31) with phase continuous changes in frequency so it probably wouldn't matter if you were driving it hard enough to produce ALC. I don't think that would distort the signal.

    That said, it's intended for low power so if you've generating ALC then you're probably running too much power but... I guess it depends on the radio and how its ALC works.

    I've had some fun with JT65-HF. It seems to be a popular mode in South Africa for some reason.
     
  2. WD0DXD

    WD0DXD Ham Member QRZ Page

    I would have to agree with that, I got my first SA contact using JF65-HF just a couple of weeks ago.
     
  3. G0GQK

    G0GQK Ham Member QRZ Page

    Being the old cynic that I am, some of these comments made me smile !

    "I made some great contacts, 30 yesterday,South Africa and then Hawaii, the contact is limited to 13 words, I couldn't hear the transmission, or see a trace on the screen,and I could still make more contacts when I'm fast asleep doing Zzzzzzzzzzzz ! " Ha ha ha, and they call this ham radio, Ha ha !
     
  4. KM5CU

    KM5CU Ham Member QRZ Page

    Well, on my end, I seem to be having technical difficulties which are making me not like this JT65. At first I thought it would be interesting since for me very low power has a special appeal and this mode promises to be good for low power, but... so far I have made one "contact" which turned out somewhat bizzare. I can hear a few stations, but virtually no one hears me with less than 10W. The JT65-HF software not always decodes what is plainly audible (no, it's not timing and it's not a slow computer, so who knows!). So I guess I'll try it again, but so far I am not impressed. PSK31 was so much easier to implement and I am up to 10 wpm on CW... now that's fun!
     
  5. VE3PP

    VE3PP XML Subscriber QRZ Page

    I have to assume you have the program running in the Enable Multi-Decoder mode when you are listening and trying to decode the signals.

    You mentioned timing. Remember you have to make sure the computer is dead on time, I use NISTIME 32 software to keep my CPU clock on time. Otherwise I can not decode any signals if the CPU clock is off.

    As for your power. I use dipoles and find 10 watts sometimes doesn't cut it. Of course if all depends on the propagation.

    Keep trying, you will make it work!
     
  6. KD4MOJ

    KD4MOJ XML Subscriber QRZ Page

    KM5, like FMC said, check the Muli-decoder and make sure that your clock is accurate. Also what is your receive sound level number showing? (top left of screen). I found that if the level/number is too high, you will have difficulty in decoding. I try and keep my levels near zero. If you want to try a sked, lemme know.

    Also on your transmit, are you showing any ALC? If so, that could be your transmit issue.

    I use 10 watts (20 max) most of the time so that should not be the problem.

    ...DOUG
    KD4MOJ
     
  7. AE5YJ

    AE5YJ Ham Member QRZ Page

    I finally was able to do a JT-65 QSO (thanks KC0EM) tonight. Oklahoma to Minnesota on 10-15 watts, not bad considering the QRN on 20 this evening. Getting the program to run on my computer (vista 32 bit) and getting it to work correctly with the signalink USB turned out to be quite a challenge. I had to fool the program into thinking it was a stereo input device, and then I couldn't find a working time sync program that would actually sync correctly. Most that I could get to work with vista still had a deviation of 8-12 seconds no matter what server I chose. At the advice of others, I downloaded the Chronos sync program and it worked like a champ.

    After all that PITA with my computer, interface, and operating system, I finally got OTA tonight on JT-65. Felt great, even if the format is a tad succinct.

    Best regards, Andy
    73 KD5OUW
     
  8. KF5FEI

    KF5FEI Ham Member QRZ Page

    Not sure about Vista, but on the old XP box, if I double-click on the clock and bring up the date / time screen, one of the tabs is for syncing. Mine was set for a Microsoft server, but I changed it to the NIST server, IIRC.
     
  9. K0PVW

    K0PVW Ham Member QRZ Page

    HELP!! I just cannot seem to get JT65 going I heard some signals on 12M today (yes 12M). I frequent HRD/DM780 for PSK use, what should I be using or need to use to get this mode, I could hear some JT65 signals coming in but have yet to figure out how to recieve them or decode them. If you want you can PM me here to point me in the right direction. Thanks Rob
     
  10. G0GQK

    G0GQK Ham Member QRZ Page

    I thought I'd try this JT65 a couple of weeks ago, its definitely different, especially as my two downloads can transmit but not receive messages.! Despite help from a number of users it still won't produce messages. Weird.
     
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