W8LT - Alive again!
After a long time of being QRT due to antenna problems W8LT, The Amateur Radio Club at The Ohio State University, is back up and running! Several of us spent a couple hours last night, with the assistance of the OSU Maintenance Department to access our tower and antennas, to do some much needed repairs.
The triband yagi we have has been disconnected due to a broken connection since last year. As we got up there to inspect it the cable is hooked to the beam using ring terminals. I have not seen a set up quite like that before, most of the beams I have worked on have had SO-239's or N's for screw-on connection to coax. I guess if you are putting up a big HF beam antenna chances are it is going to stay there so direct coax attachment is OK. Anyway, one of the ring terminals broke.
As a cause of the ring terminal breaking - there is a 1:1 coax choke wrapped on a 6" piece of PVC that is hanging from the cable. I am sure the added stress of this is what did the job on the connector. One of the guys secured the choke to the mast to take the load off of the cable, as well as gave the cables all plenty of room to rotate.
While up there we calibrated the direction of the antennas better. They weren't even close before and the rotator we have is not easily calibrated from the box. Being up on the tower working on the beam was a perfect opportunity to change the azimuth.
The coax to our 80m dipole had been worn through for a LONG time - how long is any one's guess. We did an inspection trip up to the roof some time in the past year and discovered that the coax was rubbing on the shingles when the wind would blow the antenna. The shingles wore through the coax - partly through the dielectric.
I cut the original cable where it comes out on to the roof and spliced in a good run of RG-213 using a PL-259 on the original cable and a barrel connector between. Though there is some insertion loss with the components I think the original 250' run of RG-8x has enough attenuation that the insertion loss of the connectors is negligible.
After a quick run-through on the bands at the station everything seems to be fine! The beam is 10, 15, and 20m and the wire is 80m but resonant at 75m (the SSB portion of the 80m band, upper end).
The next challenge - getting back up on Lincoln Tower to service our aging repeater on 442.600mHz.
Those that helped out know who they are and I think everyone is grateful for the fixes! Hopefully the rest of you will be hearing lots of W8LT on the bands from now on!
The triband yagi we have has been disconnected due to a broken connection since last year. As we got up there to inspect it the cable is hooked to the beam using ring terminals. I have not seen a set up quite like that before, most of the beams I have worked on have had SO-239's or N's for screw-on connection to coax. I guess if you are putting up a big HF beam antenna chances are it is going to stay there so direct coax attachment is OK. Anyway, one of the ring terminals broke.
As a cause of the ring terminal breaking - there is a 1:1 coax choke wrapped on a 6" piece of PVC that is hanging from the cable. I am sure the added stress of this is what did the job on the connector. One of the guys secured the choke to the mast to take the load off of the cable, as well as gave the cables all plenty of room to rotate.
While up there we calibrated the direction of the antennas better. They weren't even close before and the rotator we have is not easily calibrated from the box. Being up on the tower working on the beam was a perfect opportunity to change the azimuth.
The coax to our 80m dipole had been worn through for a LONG time - how long is any one's guess. We did an inspection trip up to the roof some time in the past year and discovered that the coax was rubbing on the shingles when the wind would blow the antenna. The shingles wore through the coax - partly through the dielectric.
I cut the original cable where it comes out on to the roof and spliced in a good run of RG-213 using a PL-259 on the original cable and a barrel connector between. Though there is some insertion loss with the components I think the original 250' run of RG-8x has enough attenuation that the insertion loss of the connectors is negligible.
After a quick run-through on the bands at the station everything seems to be fine! The beam is 10, 15, and 20m and the wire is 80m but resonant at 75m (the SSB portion of the 80m band, upper end).
The next challenge - getting back up on Lincoln Tower to service our aging repeater on 442.600mHz.
Those that helped out know who they are and I think everyone is grateful for the fixes! Hopefully the rest of you will be hearing lots of W8LT on the bands from now on!
posted by Steve at
11:35 PM
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