I’ve finally got around to installing by base station 2m/70cm antenna no more using the crappy mag-mount!

The Diamond X-50A antenna was my antenna of choice after sizing up the chimney stack and reading some good reviews.

I also needed a way of mounting to the chimney - I sourced a 5ft mast from Home Depot and a Channel Master 9067 chimney mount.

Finally, from Ham Radio Outlet (one of the few brick and mortar stores I still visit), I bought 65ft of LMR-400 (PDF specs) and 30ft of LMR-400 Ultraflex (PDF specs). These cables are made by Times Microwave and so far seem to be exceptional quality.

I bought this coax as the loss figures for VHF and UHF were the lowest I could find.

The install wasn’t too difficult. I installed the Chimney Mount to the chimney (be careful of the stainless steel straps, they’re sharp and I have the scars to prove it), pulling the straps with pliers before crimping them to the brackets. The brackets then adjust with a pair of bolts, making the last bit of tightening possible with just a wrench.

Once the mount was installed, I simply installed the mast, which tightens with 4 bolts to the clamp, and popped the antenna on top. I also drilled a hole in the mast to mount a screw through the clamps to stop the mast rotating. Now it got windy, and I called it a day for now…

The next day was about cabling, so with my 65ft of LMR-400, I attached a PL-239 and climbed up to the roof again to install.

Of course, the PL-239 would not fit through the mast - damn! The mast, after all, was designed for TV antennas and a smaller connector would fit through easily. Still, I needed a short patch lead, so I chopped 1m of cable off, threaded it through and attached a new plug. After securing everything, and double-checking all the nuts and bolts, I walked the cable across the roof (I’ve not yet found a good way of securing cabling on the roof), and down the side of the house closest to the basement window where my office/shack is located.

I quickly popped the cable through the window, attached another PL-239 and connected it to my IC-7000 via an SWR meter and threw out a test transmission.

I’m happily seeing S9/S9+ from the local repeaters on VHF and UHF, with an SWR of as close to 1 as I reckon is possible. Now I’m looking forward to participating in some of the Denver area Nets more frequently.

Next step, lightning protection! We get a lot of lightning here in Denver, and currently the manual disconnect will have to do, but getting some expensive copper from the roof and into the ground is a high priority.