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Arrow antenna w/duplexer and TH-D72

Discussion in 'Satellite and Space Communications' started by K9IR, Jul 6, 2021.

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  1. K9IR

    K9IR Ham Member QRZ Page

    I'm totally new to amateur satellites and just started practicing tracking them on RX before I try for QSOs. I own an Arrow dual band portable antenna with the duplexer. My understanding was that I would need the duplexer if I used the antenna with an HT that doesn't have a built-in duplexer, e.g., Yaesu VX5-R.

    I have since acquired a TH-D72. Can I use the TH-D72 with the Arrow antenna without any changes to the antenna -- in other words, with the antenna's duplexer inline?

    I expected I would need somehow to remove/bypass the antenna duplexer and use the D72's own duplexer, but then I read this on the Arrow website:

    "Q. I have a Full Duplex, Dual Band Radio with a built in duplexer, why do I need another Duplexer ?
    A. That is why, Your Radio only has one Connector, the Antenna has two. (1 for VHF & 1 for UHF)
    The 10WDuplexer allows you to hear the down link while you are transmitting.
    It also has the coax cables to connect your radio to the antenna."

    This suggests I can/should use 2 duplexers, which seems....odd.

    If in fact I need to remove/bypass the antenna's duplexer to use this antenna with the D72, what is the best way to do so? I've taken the duplexer out and have seen how the coax runs are soldered to the duplexer PC board, just not sure on the best way to consolidate the coax leads from the 2 driven elements to a single feed to the D72 -- without the antenna duplexer in between.

    Thanks for any guidance.

    73 Paula k9ir
  2. N6MST

    N6MST Ham Member QRZ Page

    Your TH-D72 has one antenna connector. The Arrow has two. You need some external device to manage that. Leave the duplexer in the Arrow. It works great.
  3. K3RLD

    K3RLD Ham Member QRZ Page

    The statement of the duplexer in the radio itself is confusing and should just be ignored.

    As N6MST suggested, for an Arrow, it should be TH-D72 to coax to duplexer to 70cm and 2m antenna.
    WK4LR likes this.
  4. N4UFO

    N4UFO Ham Member QRZ Page

    That is the entire purpose of the duplexer.

    In TV antenna terms... one is used as a splitter, the other is a combiner.

    Last edited: Jul 6, 2021
    K9IR and K3RLD like this.
  5. N4DJC

    N4DJC Ham Member QRZ Page

    You don’t need to do anything to the Arrow, just hook it up to the D72.
  6. KC3RN

    KC3RN Ham Member QRZ Page

    WK4LR and KS1G like this.
  7. K9IR

    K9IR Ham Member QRZ Page

    Tnx much for the diagram -- very clear now as to the function of each.

    And many tnx to everyone else who replied; I understand the "system" much better now. FYI I do have the SMA to BNC adapter for the D72, so back to tracking passes and trying for a QSO ;-).
    N4DJC and KC3RN like this.
  8. W4SEX

    W4SEX Ham Member QRZ Page

    Any suggestions on a duplexer/diplexer to use with another brand of antenna other than an Arrow? Brand and model number would be great.
  9. WE4B

    WE4B Ham Member QRZ Page

  10. N4UFO

    N4UFO Ham Member QRZ Page

    WD9EWK and WE4B like this.

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