Interference Problem Solved

For the category "better late than never"...

Before I left for Texas for a month, I disconnected the antenna cables to my Ten Tec Jupiter HF  rig and my Yaesu FT1900R 2 meter rig.  When I got back and reconnected everything,  I had major QRN on 2 meters. People could hear me fine, but reception was spotty at best.  

I tried moving the cable around with no success.  The only difference from before the trip is that central air conditioning unit was on.  I never got motivated to get into into in detail, because HF was fine (I thought) and I use 2 meters more for mobile.

This past weekend we had an ARES drill for which I was assigned to operate my base station. I turned off the A/C--no difference on 2M.  The next suspect was the computer, but that's always been right where it is.  I shut the computer down and the static disappeared. I looked online and found that the monitor may be the problem.  I tried just turning off the monitor without shutting down--that was it.  Brain jock that I am, I ran the antenna cable behind the monitor.  I moved it, running it under my desk to the Yaesu, and that was it.

We were also operating on 40 meters.  I was getting static there in about a 3kHz range. Since the radio gods have a sense of humor, the frequency we used was right in the middle of that range.  It turns out that the source was the A/C--when the unit switched on, I got static.

Moral of the story: don't run antenna cables behind a computer monitor, and A/C has potential  to produce interference.

On the air!

As described in  this post  the antenna (G5RV Jr) was mounted yesterday. Today, we finished the connections (see photo), and hooked up the Ten Tec Jupiter.

Ladder line connected to coax via a juntion box, to the balun and off to the rig

I was able to hear a lot on 20 meters and some on 40.  It's tough to break in at times, and it's not always clear whether I'm not getting through or some one else is transmitting over me. Very often, you only hear one side of a conversation.  For example, I could hear someone in the Czech Republic clearly. At one point he was talking to someone in Connecticut, probably 200-300 miles from hear, but I could not here the Connecticut station.  Propagation is funny like that.

I did check into a marine net just to be sure I was getting out, and a relay station in Georgia confirmed the check-in. Later I spoke with someone in Portugal and someone else in Nicaragua.  This is cool. Tommorow morning I'll try ECARS (East Coast Amateur Radio Service) to see how I do on 40 meters.

G5RV Jr mounted--almost all set

On the house (middle)--J-Pole for 2 meters on the left

G5RV Jr on the mast with balun and juntion box

I wanted to get my new antenna mounted and installed yesterday (23 April) so I could get on the air for Marconi Day.  Unfortunately, it rained and we decided to be safe.

Today, we go the antenna mounted on the house and ran the horizontal wires out to trees, The job went smoothly almost without issue.  The only problem was that the ladder line extended down farther than I expected. We measured, and it was 19+ft.  I went back and checked the specs, which say 16ft. I went to my 2 meter rig and raised a local ham with the same antenna, and he verified the 16ft. 

So, we took the antenna down, cut the ladder line down, desoldered the existing connection from ladder line to the SO-239, and soldered the shorter piece. Then we re-mounted the antenna and ran the horizontals out to trees in the back yard. We used ropes connected to the insulators to secure the antenna to the trees, and inserted 24" rubber bungees for strain relief.

By that time we were ready to call it a day.  For tomorrow:

1. mount the choke balun on then house
2. mount a waterproof juntion box next to the balun
3. connect the balun to the ladder line inside the junction box
4. connect coax to the balun, with a lightning arrestor  between them
5. ground the lightning arrestor to the ground rod
6. run the coax through the wall to the shack and connect to the HF rig
7. figure out what I need to do for station ground
8. get on the air!