How to attach a "random wire".....

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KJ7OTM, Jun 19, 2021.

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  1. WA7ARK

    WA7ARK Ham Member QRZ Page

    Driving a wire directly without a ground system while expecting the AC house wiring to act as the ground system is a lot worse than "not ideal"! How about just plain naive!

    You might be able to receive that way, but all hell breaks loose when you press the PTT.
  2. N3PM

    N3PM Ham Member QRZ Page

    I used a 75' ft wire and a banana plug directly to my Viking Adventurer. Worked fine.
    Mike N3PM
  3. W2SGM

    W2SGM XML Subscriber QRZ Page

    Can the neighbors hear you in their doorbell buzzer? :D
  4. WA7ARK

    WA7ARK Ham Member QRZ Page

    Likely that was in 1958, before solid-state devices proliferated in consumer electronics...
  5. N3PM

    N3PM Ham Member QRZ Page

    Close, 1964. The book said 75 feet. Out the cellar window and up in a tree. The ground was the brass water feed to the building. The rcv antenna was a "Tee" that started at the chimney chase in the cellar and ended in the attic. Back before I didn't know it wasn't supposed to work.
    Mike N3PM
  6. KI5OMM

    KI5OMM Platinum Subscriber Platinum Subscriber QRZ Page

    IMG_3704.JPG In my tuner (MFJ-961) I have a random wire antenna post in the back of the unit as well as two additional posts for a balanced line. Inside is a 4:1 balun. I've not used it, but I suppose that's what it is for. I've never seen it on newer units though.
  7. N3PM

    N3PM Ham Member QRZ Page

    Maybe some clicks in the phones....
    Mike N3PM
  8. WA7ARK

    WA7ARK Ham Member QRZ Page

    KI5OMM and KP4SX like this.
  9. WA7ARK

    WA7ARK Ham Member QRZ Page

    Well, you did have a wire from the transmitter chassis to the cold water pipe. That works better than not having that wire.

    Without that wire, the only "ground" would have been via the transmitter's AC-line cord, into the AC-wall-outlet, along the in-wall house wiring, through the circuit-breaker/fuse panel, and then back into the electric utility over-head wires and the single ground rod under the electric meter base or possibly a wire from the fuse panel to the same cold water pipe you used...

    The problem with relying on the house wiring (if you dont have a "local" RF ground connection direct to the rig/tuner is that the house wiring path is much too long and that when you transmit, and RF can get into every AC-powered device in your house, such as entertainment systems, modems, networks, computers. Even worse, if you use the house wiring as part of your antenna, the RFI produced by every switching power supply in the house now has a direct path right into your receiver.
    Last edited: Jun 20, 2021
  10. KG7WGX

    KG7WGX XML Subscriber QRZ Page

    I should add, for full disclosure, that the Elecraft KX3 (and especially the KX2) are marketed for portable operations, and the instructions for minimal antennas reflect that.

    There are lots of success stories of folks using a directly connected wire / counterpoise off a picnic table. At 5 or 10 watts. With a battery for a power supply.

    The manuals do not go on to mention all of the problems of selecting and installing other antennas which might be used for a home station. Just because they are not mentioned does not mean they do not exist.

    All kinds of permanent station issues like lightning arrestors, ground rods, and HVAC variable speed motor noise disappear on a SOTA or POTA activation.

    However, if you are not careful, you can discover that your field operations had no trace of the neighbor's solar panel controller noise, until you decided to "go green" and get a cheap solar panel controller for field ops. Or, you can find out that RV inverters are not necessarily as clean a source of AC power as your local power company.

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