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Rockmite Log 22/11/29 : Antennas, broken keyers, and SWR meters

 Based on comments from the RSGB dipole antenna notes, I'm back to thinking I should try the 'radio in the middle' dipole configuration for the Rockmite. The page mentions that the coax leading to a dipole can pick up a noticeable amount of noise without a balun. I have a Rockmite board already wired up this way. The issues with the radio in the middle mode of operation are:

  • Biggest of all in this climate: moisture! I currently house the radio bare between the antenna wires. It's very, very foggy here on occasion. That, I suspect may also kill propagation though, so in its own way may not be an issue.
  • Obtaining the necessary length of CAT-5 wire to carry power, audio, and keyer signals
  • Tension relief for the antenna leads that hook directly into the board. (Especially important since the tree suspension system uses tree branches in conjunction with twine to support the antenna as close to horizontal as possible using increasing amounts of tension.
On a pragmatic note. The keyer—at the moment, it looks like it's the button itself—broke last night. So, I've got to setup a small soldering station this morning to make the whole thing better. A bit of a chore. It's that far left button (for dits) shown in the picture below.



OK! The key's fixed! 




I setup a small soldering station in the house (we got a deal from Radio Shack during hte pandemic)


The bad button's on the left. I moved it to the unused right-hand button with under the board wiring this time.



The underboard wiring seems to have fixed the issue I had with the headphones 'singing' when they were near the keyer.

Before I move too much farther along with this, I need data on how well the current antenna operates. For example, do I need insulators between the antenna and the twine supporting it? One way to answer that question would be to look at the standing wave ratio of the antenna, (SWR), and for that I'll need a low-power SWR meter like this one from lloydm.net.


Operations:
Moving to the other side of the hill, (away from SF and towards the Southeast Bay), worked! No QSOs, but the RBN did pick up the station! Also! The higher antenna seemed to haved helped with signal strength into Canada. Note the 5 dB increase in signal to noise ratio!
The noise that was present when looking at town from the other tree setup is gone in this location.




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