TV Antenna Issue

[kenn]

I've just read the owners' manual for that antenna.

Just running the cable inside the mast shouldn't make that much difference. I'm a bit suspicious that there may be some other issue, like for some reason when you ran the cable inside the mast, there was also a connection problem. When the cable was inside the mast, did you connect/disconnect the antenna power, and what difference did that make?

IF further tests give you the same results (ok with cable outside, lousy with cable inside mast) I would consider just keeping the antenna loose, and hoisting it on a halyard or flag line when in port. For local reception it won't matter alot that the antenna isn't on your mast top.

 

[wonkodsane]

At the time of installation I coated the connections with a dieltric grease to prevent corrosion. The product I applied is "Super Lube". The product states it is a "excellent dielectric and is impervious to salt water". Do you believe otherwise? Next time I go up the mast I will disconnect the antenna and post the results. Your expertise is much appreciated.

Keith

Dielectric is a good idea, not so much inside the fittings, but outside of them.

Here's your test:

Get this: 75 Ohm terminator

and this: F-81 Coupler

The cheapest prices I could find on Amazon. Sadly, RadioShack no longer carries the terminator.

Put the terminator on the coupler, and then put the coupler on the end of your cable slightly better than finger tight! The fittings are 7/16", tighten them just a bit to guarantee full metal-to-metal contact within the fittings, this goes for all of your cable but be careful behind the TV as it is easy to damage that fitting. A good test of whether or not they are tight is whether or not the cable (not the fitting) will spin at all once you've tightened the fitting down. Once you've done that, hoist the terminated end of the cable outside the mast, then connect the other end of your cable to your TV.

If your TV has any reception that it didn't have when the cable was disconnected, then you definitely have bad fittings or bad cable.

And to continue about the dielectric, it won't do a lot of good in an unflooded cable unless the fittings are compression fittings versus crimp or hex fittings. Unflooded cable has a fair amount of air inside it, which expands when hot and contracts when cool, if there is water present at the fittings during the cooling portion of that cycle, it will literally suck water into the fittings and the cable. Compression fittings help by actually sealing it, hex and crimp fittings don't make a good enough seal against the vinyl of the cable jacket. Dielectric doesn't really prevent this very well unless the fittings themselves are good.

I recommend Snap N Seal, the compression tool is ~$55 and Quad Shield RG-6 fittings are $20 for 50. Like I said, be careful not to leave braid or foil from the outer layers of the cable in contact with the center conductor.

As for an amplified antenna, I'm with Kenn on this, unless you're talking about a multi-stage paddable/equalizable amplifier, the noise floor will come up just as far as the signal does, and so is fairly useless for a digital signal. Most commercially available TV amps just plain stink and that's me being polite about it.

-Scott

 

[Benny]

Installed my antenna on a pole in the stern of the boat. It is only around 6' high from the deck but I get all the digital channels in my area. I drilled a hole an used a gromet to run the coax cable inside. A Radio Shack converter box running on the inverter makes it possible to run the old flat screen TV.