"Pete C." wrote:

"Michael A. Terrell" wrote:
?
? "Pete C." wrote:
? ?
? ? Harold ? Susan Vordos wrote:
? ? ?
? ? ? Hey guys!
? ? ? We live in an area with little television reception. I've avoided paying
? ? ? for a dish, as I don't watch all that much TV. We get a PBS station, along
? ? ? with one of the Fox network stations. Good enough for us, as we get news and
? ? ? some interesting scientific shows.
? ? ?
? ? ? Ok, now my question. I have a splitter in a room that is not heated. As
? ? ? weather turned colder, I started getting a lot of blue screen on the TV.
? ? ? The colder it got, the worse the reception, until it got to the point where
? ? ? the TV was off more than it was on. About a week ago, I lit the boiler
? ? ? in the room where the splitter resides. Suddenly, great reception. When
? ? ? the room cooled off, after turning off the boiler, it was back to blue
? ? ? screen once again. Heated the splitter and got service back. When it
? ? ? cooled down, it was, once again, lost. Replaced the old splitter with a
? ? ? new one, which improved reception, but did not eliminate the problem.
? ? ? Finally hung a small light bulb near the splitter, which I figured would
? ? ? keep it warm. Sure enough, we now have great (albeit limited) reception
? ? ? once again.
? ? ?
? ? ? Anyone care to offer a reason for poor performance when a splitter cools off
? ? ? too much? I would suggest that it was in the 40 degree range, not
? ? ? freezing. Why would it cooling off make a difference? I fully expected
? ? ? that it wouldn't be temperature sensitive.
? ? ?
? ? ? Harold
? ?
? ? Nothing to do with the splitter, it's the connections to the splitter,
? ? what we termed "suck out" at the cable company when it happened on line
? ? gear. What you have is "F" connectors which are little more than nuts
? ? crimped onto a piece of coax with the copper coax center conductor
? ? acting as the center pin for the connector. If that center conductor is
? ? cut too short when things get cold and the metal contracts it will pull
? ? back into the coax and out of the connection in the splitter or
? ? whatever. The connections on the hard line coax on CATV line gear are a
? ? little different, but the same effect can occur there with the center
? ? conductor pulling out of the connection if it isn't cut long enough.
?
? Actually, it was the opposite on hardline. The foam insulation
? slowed the contraction of the inner conductor and caused the shield to
? pull out of the connector. BTDT, and needed the propane torch to thaw
? out hands.

Not in our experience in the frozen northeast. The hardline connectors
grip the AL shield/jacket quite well, and the span between poles always
has a slack loop to allow for contraction without pulling on the
connectors. The center conductor which just connects inside the line
device with a screw terminal lug is where some inexperienced techs would
clip the center conductor off just past the lug, leaving only 1/4" or so
before the conductor would pull free of the contact. Leaving a good 3/4"
past the lug prevented the problem. Of course on line gear the problem
is worse than on home gear since RF can bridge a bad connection, but the
60VAC line power for the amps can't.

Raychem developed their ceramic hardline connectors which helped.
Most of our suckouts were underground cables, till we switched from the
traditional Gilbert connectors. The Raychem was better, but over time
the aluminum skin would fatigue and break within a few inches of the
connector.

60 VAC modified sine wave at up to 30A was part of what caused the
hardline suckouts. The center wire stayed warmer because of current
crowding.

This was all in Delhi Township, near Cincinnati, Ohio.


The real fun was getting CG&E to let use mount a large steel NEMA box
on the side of one of their power poles to house an RCA Heterodyne
Signal Processor to convert T-7 to Ch. 12 at the interconnect point for
two community loops. Mid split to sub split. The lead tech complained
that I was off by .5 dB when their community loop was powered up for the
first time.


? Funny that you mentioned CATV. I have a pile of Agile Modulators
? sitting here to convert to the old US FM band, and an agile processor.
? I wish that I had ahd a few of these 25 years ago when I repaired
? headends and designed interconnects between community loops for seperate
? CATV systems.

I've got a couple modulators kicking around as well. Not much use any
more in these ATSC days though.


What brand(s)? Are they home units, MATV or CATV? I've worked with
Holland, Blonder Tongue, Phasecom, RCA, Catel & Scientific Atlanta. I
was repairing BT strip amps back in the early '70s, and some Vicoa 12
channel trunk amps in the Army. I repaired 300 & 450 MHz Sylvania line
equipment, which was later sold to Texscan. I wave a Wavetek SLM, along
with a portable Sadelco, a SAM and a Texscan sitting around


? http://www.ebay.com/itm/270834480453 is a cheap 10 dB amp
? that would likely help in a marginal area.



An amp located near the antenna, or there are some pretty good amplified
unit antennas available these days.


With digital, it's the recovered data that matters, so an inline amp
at the splitter would help. Those bullet amps were fairly low noise 25
years ago in fringe locations, so if the sets work most of the time, the
extra 10 dB should stop the problem for under $20. It might even get
him another channel or two. With digital the final BER is what
determines the picture quality. (Bit Error Rate).