[Complete] HF Station off line

Interest Groups Amateur Radio
#1

Placed an antenna analyzer on the HF antenna this evening. The system is resonant… just not in any amateur bands. :frowning:

I have disconnected the antenna and placed a sign on the rig noting that the station should not be used and the antenna is disconnected. @ke5bud is going to try to get on the roof and tack down the ladder line to see if this helps as the past few days have been the first significant winds we’ve seen.

Once that is done I will put the analyzer on and run the checks again. Good would be SWR under 3, Better would be under 2, and Best would be as close to 1 as possible. Yes, we have an antenna tuner. However, resolving the underlying problem will make the equipment last longer.

Below are a few graphs. One being the entire HF band. One for 20m and one for 80m.

https://drive.google.com/folderview?id=0ByomtnC1z9CtcXdlZF9SbTl1VWM&usp=sharing

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#2

HF station is back on the air. The antenna is still not tuned for ham bands, but just please, please, please be sure to use the tuner. Re-tune every time you make a significant change in frequency. Especially if you change bands.

#3

I’m at the space tonight, and I noticed that the VHF/UHF rig is plugged into the antenna, and there are storms in the area. Should we have a “disconnect it after you are done” policy? Also, what are our long-range plans for static protection (Polyphaser GDTs, etc.)?

N0ZGO

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#4

Sounds good on the disconnect it after use policy. I will build this into the desk as well. As for long range we have not covered that yet.

#5

The station is back up and running, please remember to connect the antennas leads before using the radios. We ask that after every use you disconnect them for safety of the radios and building.

The Thicker low loss line is for the 2M/70CM and the Smaller coax is the HF with a BNC connector.

#6

I’d like to propose that we get two of these, one for the HF rig and one for the VHF/UHF rig. The switch includes static protection and a “Grounded/No-Antenna” position. This would also allow for later expansion of additional antennas on both rigs.

[edit: also saves wear and tear on the rig connectors]

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#7

Right now we’re holding off on this because we don’t want to divert any direct hits to our ground, as it is the buildings ground and not a ground spike. Once we get the desk assembled I will be tackling the ground and looking to install a couple of these at least.

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#8

Ok, but I caution you that any direct hit will likely vaporize that tiny little wire inside of our coax, the shield itself, and anything else happens to get in the way as it turns to plasma. :smile:

A “real” lightning arrestor setup would have that equipment up at the antenna itself and a 2-4 GA lightning conductor coming down the side of the building. Ideally, the inside equipment is switched to the OFF/GND selection on one of those switches. You want to get the lightning pulse to travel outside of the building to ground. As an aside: J-poles are great for this as they can be at DC ground and clamped directly to this wire, which also prevents static build-up due to wind, etc. [edit: I’m wrong! http://www.hamradio.me/antennas/j-pole-antenna-should-i-ground-it.html]

Some great articles from the ARRL on the subject:

http://www.arrl.org/lightning-protection

Disclaimer: I am not a professional engineer and all of my advice could be complete baloney. Use at your own risk.

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