In keeping with the current theme of antenna troubles...
On November 28, 2010 my wonderful Delhi VU-936SR plus UHF Power Zoom snapped in two after 16 years on the job.
I was in the yard making one last dash to pick up the leaves but didn't look up as I normally do. I was taping the Packers on WLAX for later. I had to leave and didn't come back until after dark. I then noticed WKBT cutting out. I backed up the tape and saw that WLAX started cutting out around 4PM. WKBT never cuts out, so I stuck my head out and looked up. I could see something swinging in the breeze at the top of the tower. When it was light out I saw that the UHF portion snapped and was dangling by the twinlead going to the preamp. It held long enough for me to climb up on a relatively calm day and cut it loose and lower to the ground.
The red circle in the second picture is the twinlead. It was enough that I could still pick up all the local stations. But later KYIN 24 (18) started acting up, do I dug my 20+ year old Radio Shack U-120 out of mothballs and set it up inside. As Doctor Who Series 5 was about to start.
The third picture is the UHF section and shows that it was a bad tear, not a clean break. Not sure what/how it happened.
To "celebrate" the 4th of July I spent three hours unbolting and lowering the VHF section to the ground. Then the rotor as it stopped working also. Being unbalanced like that probably wasn't any good. When I opened the door to detach the wires, all the screws had fallen out.
I then hauled up the aforementioned U-120 and bolted it in. Aimed it towards the WLAX/WXOW/WHLA tower, best guess. Will see how reception holds up over the next several days, but better than I thought. Locals are in the 80s or higher for signal strength including KTTC. (DigitalStream converter)
WLAX and WHLA are now coming in, mid 50s. Even WKBT was coming in (low 40s), not sure how long that will last. WXOW, not very good.
Was picking up TPT 2 (34, 23), WCCO 4 (32) , KMSP/WFTC (29), WUCW 23 (22), and KSTC 45, around 50. Will see how those go over time.
With the VHF section on the ground I was able to look at the tear on that section. It snapped right at the support for the upper and lower beams.
Now I will have to find a replacement as those Delhis are no longer made. That setup pretty much brought in everything. The only stations I couldn't get were 18 (15) and 48 (49) out of Chippewa Falls/Eau Claire. WEAU on 13 was spotty. I never had a problem with analog 13 nor the digital transition channel, but when they went back to VHF at hair dryer power levels it became problematic.
Either allow digital VHF stations to transmit full power as before, or drop VHF altogether and use it for emergency frequencies instead of chopping away at the UHF spectrum. No VHF would make antennas easier.
Rarely picked up the Ion Affiliate out of St Cloud, But I could usually pick up KEYC 12 Mankato at night. Clear views of the northern, western, and southern horizons at the top of the tower (Delhi 70 foot).
So I would like to keep that reception. Gangbusters UHF reception is essential as I must
get the Packers. As there are no VHF-Low stations in range, I suppose I could settle on a VHF-High antenna. But then I would lose FM reception. I have tuned into the Packers Radio Network out of Eau Claire (100.7) in the past, so I would prefer to keep that ability.
I changed the rotor for the first time in 2010 (it hadn't worked in years). My feet in clodhoppers don't fit well at the top of the tower, so I made a footrest out of a scrap 2x10 and clamped it to the rotor plate. This gave me enough height to maneuver the antenna around.
I don't want to repeat that again, so I thinking of bolting two thrust bearings into the plates and find a way to mount the rotor below. The bearings should extend the life of the rotor, but if I have to replace it, I won't have to be semi-precariously perched on a footrest. Plus I could raise and lower the mast to get access to the antenna as needed. I don't intend the rotor to bear any vertical weight.
Because the holes in the plate have three inch spacings, I think the only bearing that will fit is the Delhi BBMB. Yaesu appears to be metric. If there are alternatives, I am all ears.
I saw some of the posts about masts. Right now Menards has galvanized pipe on sale. My current mast is 1 1/2 inch OD, wall thickness 1/16 inch. The masts on sale are 1 3/8, 1 3/4 and 2 inches OD. About 1/8 inch wall thickness, should be stiff enough. The BBMB bearing max diameter is two inches, but pipe that diameter would be awfully heavy to haul up and maneuver, plus could be difficult finding a rotor and antenna clamps to fit.
So I am wondering if there is anything out there comparable in performance to a VU-936SR???