A M Crystals

Discussion in 'Amplitude Modulation' started by W4WOZ, May 7, 2018.

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  1. W4WOZ

    W4WOZ Ham Member QRZ Page

    Hi everyone.

    I have acquired a Knight Kit T-150 Transmitter and looking for some A M Crystals...3885 and 7290...if you have anything please contact me...w4woz at live.com

  2. VK3YE

    VK3YE Ham Member QRZ Page

  3. AC0OB

    AC0OB Platinum Subscriber Platinum Subscriber QRZ Page

    Congratulations as they are great rigs. I have upgraded mine for better audio and modulation capabilities.

    An alternative might be:

    http://www.af4k.com/crystals.htm (see center of Page)

    and resort to a circuit shown below, or purchase a DDS kit:


    Attached Files:

  4. W4WOZ

    W4WOZ Ham Member QRZ Page

    Thanks to both of you who replied. Seems af4k is my best shot so far. But I am still looking around.
    Maybe someone in the Ham world has these crystals.
  5. KE4OH

    KE4OH Ham Member QRZ Page

    Bry, AF4K, is a good guy and will ship crystals fast if he has the ones you want in stock.

    Having said that .... the VFO in the T-150 isn't THAT bad! Just don't pound your fist on the table while operating and stability should be fine.

    I highly recommend a muffin fan on top of the cabinet. The heat that the T-150 throws off is just incredible.
  6. K4KYV

    K4KYV Premium Subscriber Volunteer Moderator QRZ Page

    That rig needs some improvement in voltage regulation to the VFO, or better isolation from subsequent stages. I remember when the T-150 first came out in the early 60s, they were easily identifiable over the air, stood out like a sore thumb, by the 'wobbulation' of the carrier under modulation. The frequency seemed to shift at syllabic rate, not actual FMing with the audio, so I suspect something in the controlled carrier function was pulling the VFO.

    A few of them sounded quite good after the owner trashed the controlled carrier AM and used a plate modulator.

    Regarding crystals, isn't it strange how nearly all amateur band crystals have disappeared from hamfest flea markets, yet there are loads of oddball non-amateur frequencies available? Where did they all go, now that not very many hams are actually using crystal control these days.
    N2EY likes this.
  7. W4WOZ

    W4WOZ Ham Member QRZ Page

    Thanks for the info about the T-150...I do plan to do the muffin fan on this rig...And the crystals?....havent found any yet....
  8. W4WOZ

    W4WOZ Ham Member QRZ Page

    I want to thank everyone who commented about this .I have got some crystals from AF4K and looking at some mods on AMfone...very interesting stuff. I am hoping for some radio active hams on AM real soon.....73's
  9. K5UJ

    K5UJ Ham Member QRZ Page

    Guys are mining real FT-243s at hamfests and hanging on to them, especially if they are for popular AM frequencies like 3880. By the way other big rocks are okay for vintage gear too. The problem with the HC-6 wafers is they don't always handle vintage current. I'd say rigs made after 1950 are a safe bet for the newer xtals. The reason they're getting hoarded is they are getting hard to find and an assortment of crystals is great when you've just finished fixing up a rig and want to test it on the bench.
  10. W4WOZ

    W4WOZ Ham Member QRZ Page

    Well K5...These guys are going in a Knight T-150 ,so I am hoping for the best..

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