I have done some reading about balun transformers and how I can connect
my existing flat antena cable to 75 ohm cable.
However, my questions is this... what if I replace the 30 year old flat
cable all the way to the antenna. Will this yield better reception?
(It is pretty good as it is.) The exiting flat cable is starting to
fall apart at some places. Currently I just have it directly wired to
my coax cable (just before it enters the house) with out any type of
transformer. The coax is properly grounded (to the circuit breaker
So my questions are these:
1. How do I connect the coax directly to the antenna? Or should I?
Do I still need a balun transformer?
2. If I need a balun transformer, does anyone know of a heavy duty
outdoor one? (Or should I build my own.)
3. Will reception improve?
Thanx to all who reply.
Yes, your reception will improve. You have a mismatched impedience
now. Yes, you need a balun transformer. Around $5 at any hardware
store, or Radio Shack. If the old cable is deteriorating, it's time
to replace it. The balun comes with about 4 inches of flat cable that
goes to the 2 antenna nuts, then the coax screws to it and goes to the
tv stuff in the house.
Just do it. It's no big deal to do as long as you can get on the roof
and to the antenna. Total cost is the balun, some electrical tape,
and whatever coax you need. Then tape the coax to the mast with
electrical tape. You dont need standoffs for coax.
(Be sure to wire brush the rust off the antenna nuts and coat them
with automotive grease.
Thanx, I'll try it this weekend. I have some high end coax cable ready
for the job. Only one more question... should I worry about the
quality of the balun transformer? The ones I have seen at Home
Depot/Lowes/Radio Shack look pretty flimsy. I know there is probably
nothing inside that should not get wet, but I still wonder...
I'm not sure what to tell you about the quality of them. I'd guess
they are all made by the same company anyhow, but who knows? Use the
boot that comes with them, and I tend to wrap electrical tape around
that to be sure it stays dry at the coax connector. If water gets
inside the balun, it's cracked and bad from the start. They are
sealed. As another posted said, replace the screws and nuts on the
antenna with brass ones if they are real rusted or corroded.
The outdoor TV antenna baluns are sealed better to prevent moisture from
getting inside and degrading the components. They also have a rubber
boot to cover the coax connector.
Here are two URL's for Radio Shack TV antenna baluns. The second one has
gold plated connectors which should make it more reliable for outside use.
Should I be worried about this? Currently the twinlead only runs from
the top of the antenna to where it enters my house. About 40 ft. Then
I have coax in my crawl space for another 80 feet or so. 30 ft of
which is just coiled and wasted. Reception for local (Sacramento)
stations is pretty good. Reception for San Francisco stations is too
grainy to watch at times. My zip code is 95682. (So I should not
expect too much from San Francisco.)
If need be I can replace the existing twinlead with new twinlead.
Should I look into this?
If you want the best weak signal reception (San Francisco) either use
new twinlead all the way from the antenna to the TV or new coax all the
way with an antenna amplifier too. You might want to consider an antenna
rotator if the local and distant stations are in different directions.
BTW- If you use twinlead, install it with a continuous twist along it's
length. Make several twists per yard. I know it's a pain to do this but
it helps to reduce the reception of noise from home applicances on the
You haven't told us what type of tv antenna you have, and whether or
not you have a rotor. To get San Francisco stations in your area, you
must use a rotor as the Sacramento stations and the San Francisco
stations are not coming from the same direction. Also, to get the UHF
stations from San Francisco, I recommend the Channel Master 8-bay
bowtie. It is very common in Sacramento to have separate VHF and UHF
antennas as it is fairly easy to get decent reception from San
Francisco, Santa Rosa, Concord, Chico, Redding, Reno, and even more, as
well as all the local stations. But you MUST have a high-gain antenna
with a narrow beamwidth. Otherwise, the local stations will interfere
with the distant stations. As in Fresno (where I now live), with a
high-gain antenna with a narrow beamwidth, it is possible to get more
than one station on the SAME channel, just by turning the antenna. I
recommend NOT using any pre-amp at the antenna as the powerful
Sacramento stations will wipe out most of the distant stations.
Generally speaking, in the Sacramento area good coax cable will work
better than twin lead, especially if you are around any electrical
interference. Also, even twisted twin line can pick up signals that
may interfere with the distant signals. But DON'T have several feet of
coax wound up in your attic. Every foot of lead, whether twin lead or
coax, adds to signal loss. Generally speaking, the antenna should be
mounted as high as possible, although this is not always the case,
especially with UHF signals. There is never a guarantee as to what you
will receive. As far as using a balum at the antenna (and at the tv if
necessary), all balums are NOT created equal. Different samples from
the same manufacturer can vary greatly in the amount of signal loss,
etc., especially at the UHF frequencies. For the antenna AND balum, I
recommend staying away from Radio Shack. In Sacramento, the most
popular antennas for picking up San Francisco, are made by Winegard and
Channel Master. The BEST UHF antenna you can use is the Channel Master
7-foot parabolic but strong winds can cause problems if the mast is not
strong enough. I used the 7-foot parabolic on a 30-ft. mast with rotor
and got excellent reception from most of the UHF stations from San
Francisco. Second best is the 8-bay bowtie. For more information,
read my article in RADIO ELECTRONICS magazine, August 1982, titled HOW
TO SELECT THE BEST TV ANTENNA. You should be able to find that issue
at a library.
I couldn't tell you what kind of antenna I have if my life depended on
it. It is big and it is very high. At least 40 feet high. If memory
serves correctly, I only have one antenna for both VHF and UHF. (Too
dark to see right now.)
As for the direction, both the Sacramento and the San Francisco
stations are in the same general direction. I am about 40 miles East
of Sacramento and given that the Sac antennas are in the Delta by
Stockton, I pick up San Fran stations as well. Ironically the station
that I really want to pick up does not come in at all, it is Channel
19. (I want my kids to watch Spanish cartoons and I refuse to pay for
cable.) I think Channel 19 is East of Modesto some place. (I had a
link to a site that pinpointed all towers on a map but I have since
lost it. Maybe someone here knows of the site.)
So as of earlier reading I was leaning towards coax, then twinlead (to
minimize loss) and now I'm confused all over again.
This is basically a summary of what I have gleaned from you gusy...
--Easy to install.
--Less suseptible to interferance.
--I have a huge roll ready for deployment.
--More difficult to install.
--Must purchase about 100 ft.
--Must purchase hardware to keep away from mast and wall.
Come the weekend, I'm doing one or the other... so I better decide by
Thanx again to all who replied.
Your best off to use RG6, if using coax. Its lower loss than the more
You can avoid all these issues by getting satellite TV! In most areas
of the country they carry lour locals.
all conveient on one pizza pan sized dish, and bets of all they have
DVR, digital tv recorders built in.
you record what you want, to watch anytiome you care to, and can skip
thru commercials. one version is called TIVO. a hour of prime time has
15 minutes of commercials, well thats now my time to do with as I wish!
satellite tv has free installs, with no commitments if you get the
right package. you have nothing to lose!
The website you are referring to is located at:
http://www.antennaweb.org/aw/Address.aspx - but be careful using this
site. With your zip code, you might get the idea that your local
stations and the San Francisco stations are in the same direction. NOT
SO. They list so many channels in that same GENERAL direction that you
really can't decipher from that website which direction the signal is
The Sacramento and San Francisco stations are NOT located in the exact
same direction. That is why you need a highly directional antenna with
a very narrow beamwidth. You can separate the locals from the Bay Area
stations. You can "pick up" the San Francisco stations when the
antenna is pointed towards the Sacramento towers, but you can get a
STRONGER signal when turning the antenna towards Mt. Sutro (San
Francisco towers), and at the same time, REDUCE the local signals, thus
giving you a stronger signal with less interference. To help clear up
the confusion between coax and twin lead -- First, twin lead must be
installed properly - not touching any metal to say the least, as it
should be a few inches from any metal. It's not good to install twin
lead between walls, etc. As far as loss goes, coax is consistant
regardless of the weather. Twin lead losses can be greater than coax
during wet or damp weather. To have low loss, twin lead must be dry.
Also, twin lead is more suseptible to breakage during high winds. You
want the SAME lead in all the way from the antenna to the television.
Don't mix twin lead with coax. You might get excellent reception of
the local channels, but it can make a big difference on distant
reception. IF your antenna is high gain on UHF, has good directional
characterics, you should easily get channel 19 from Modesto UNLESS
there is a mountain near you blocking signals from that direction.
However, channel 14 in San Francisco is also Univision. I have picked
up weak signals from channel 14 even here in Fresno. I can tell you
this - When living in Fair Oaks, I had the largest Channel Master
UHF/VHF antenna available, installed on a 40-ft mast with rotor and I
could NOT get any signal on channel 14. But my neighor had a cheap,
small antenna mounted on the chimney and got a good signal on channel
14. Higher is not always better on UHF. Also, ANY bad balum OR even
twisting wires combining coax to twin line can totally wipe out some
Here's a link to a picture of my antenna, maybe someone can tell me
what I have. Also, does the fact that the "receivers" are off place
and therefore touching affect the signal? Since I will be up there, I
will straighten them, but odds are they will get crossed again. (I've
aready fixed this in the past.)
It appears you have the Radio Shack model VU-120 antenna. The best
information I can get on this antenna is: gain is only fair to good
and directivity is probably below average to average. This antenna is
made mainly for local/suburb reception, NOT for distant stations. The
beamwidth on this antenna is NOT narrow enough - that is why you can
pick up San Francisco stations without turning the antenna. NOT A GOOD
ANTENNA FOR WHAT YOU WANT TO RECEIVE. Stick with Channel Master,
Winegard, or Jerrold brand antennas. They are built to last and have
much higher gain and much better directivity. In YOUR case, I would
add the Channel Master 8-bay bowtie antenna for distant UHF signals and
keep your other antenna for the locals. Otherwise, you are talking
about a $200 UHF/VHF antenna. The 8-bay antenna is not high priced,
and beats the UHF section of EVERY UHF/VHF antenna on the market that I
know of. But it is extremely directional and you will need a rotor.
Also, not only is the gain high and the directivity outstanding, but
the design of an 8-bay bowtie gives more "signal capture area" because
of the large screen behind the active elements. This really helps in
mountainess areas and other weak signal areas. The design of the
antenna also narrows both vertical and horizontal beamwidth, resulting
in less ghosting. If you can barely pick up a UHF signal with your
current antenna, chances are the signal will be very good with the
8-bay bowtie. And I'm talking about your current antenna with NEW
coax cable, not your current mixed lead.
More info on your antenna compared to the 8-bay bowtie on UHF signals.
The following are approximate figures based on all the information I
can find. Your antenna gives an average gain of about 6 db while the
8-bay bowtie gives an average gain of 13.0 db. Depending on the
channel, the MINIMUM gain on your antenna is about 0 db while the
MINIMUM on the 8-bay bowtie is 9.5. I don't have specifics as to the
channels on your antenna. Every 3 db DOUBLES the signal. The average
horizontal beamwith of your antenna on UHF is about 31 degrees while
the 8-bay bowtie is about 21 degrees. BIG differences. The 8-bay
bowtie rejects signals coming from the sides and back several times as
much as your current antenna.
Ok, so is it possible to have both my current antenna pointed in one
direction (minus the UHF section) and use this new antenna pointed in a
different direction? Then just combine the signal? This would give me
the best of both world w/o the need for a rotor.
Sure. Back in the dark ages, when the UHF channels went up to Channel
83, TV sets didn't have a combined antenna input, instead they had
two (usually 300 ohm) inputs, one for each band. To save cable,
VHF/UHF splitter/combiners were used if you had an all band antenna.
They're bidirectional, the same unit can be used either way. So you
can run two antennas into the one cable.
Mark Zenier email@example.com
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