On Nov 19, 6:14�pm, "Tam" wrote:
"Rich Grise" wrote in message
news
My current UHF antenna is a 14" Radio Shack clip lead clipped from the
center of my coax to the venetian blind. I have to hand-adjust it
for the channel, weather conditions, phase of the moon, etc. I can
do this because I can _see_ an indication of signal strength.
Well, with this new Fascist "No More Free TV" crap, I'm gonna need
a real UHF antenna. My budget is exceedingly limited, but I have
a supply of materials (GTAW filler rod, with some coppery-colored
coating, so it solders like a dream, and is as stiff as piano wire)
to build an antenna with.
But I've been searching the web for some weeks now, and I can't
seem to find any kind of formula, except there was this program
I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's
in Russian or Polish or Uzbekistani - one of those East Yurp
languages. Here's a screen snap:
http://mysite.verizon.net/richgrise/...rog-Output.gif
Which I went through pretty much by-guess-and-by-gosh - can
anybody read that stuff?
There are a lot of factors I don't know about, like "Tau", and
all of the specific designs on the web are flat - something is
telling me I want one of those pyramid-shaped ones, but I really
don't know the difference (between that and flat) - it's probably
something to do with bandwidth or F/B ratio or whatever.
My local library has no ARRL Antenna Book (!), and did I mention
I have a seriously limited budget?
So, how do I pursue this? It'd be nice to have a program that will
calculate the whole thing for me, but am I dreaming? If I want to
send myself to Log-Periodic School, where should I start?
Or, does anyone have a UHF-TV log-periodic design that they'd share? :-)
Thanks,
Rich
Before you get too far, be sure you know what you need. This is based on
post 2/09 channel assignments. You will need to cover either
a) CH2 - CH51
b)CH7 - CH51
c) CH14 - CH51
Tam- Hide quoted text -
- Show quoted text -
I agree. How much can a coat hanger cost?
If you are really rubbing pennies together, I would ditch the log-
periodic approach and go with something simpler, like a monopole or
folded unipole antenna. (All you need is wire.)
I just want to mention (again) here that: Hopefully, we'll be able to
knock out Ch-5 and Ch-6 from this antenna scenario very soon (and move
them to the FM Band, as the FCC is presently considering. I'm a huge
proponent of this possibility!
I will try to find the Comments link at the FCC web site so those of
you who agree can chime in....
This idea has been floated before, of course. This time it seems to
have "legs".
I don't know how much you can read into it, but... the FCC has yet to
explain how Non-Commercial Educational (NCE) vertical only stations
can obtain authorization for horiz/vertical operation once this DTV
transition occurs - which is now less than 90 days away.
There are many pending Construction Permits (CP's) and NCE facilities
that proposed Vertical-Only operation in order to protect local ANALOG
TV-6 stations. These new NCE facilities will undoubtedly delay
construction until a decision is made how to obtain dual polarization
licensing. (Due to increased transmitter power requirements and/or RF
Safety exposure issues, tower height requirements, etc..)
To date, the FCC has yet to adopt ANY relaxed TV-6 digital protection
criteria for NCE FM stations. Instead, these stations must use the
old Analog standard - which is MUCH stricter than is necessary to
fully protect a Digital TV operation!
And of course, there are only (8) full service TV's on digital channel
6. (Which is a really, really good reason to move TV-6, and possibly
TV-5 to the FM band!! -- What a huge waste of spectrum!!) Yes,
there are some low-power DTV 6's out there (translators, boosters,
LPTV's). Not very many, and all of which are in locations where other
spectrum is, or will be, avaialble after the DTV transition...
Anyway, any NCE or CP not near a digital-6 would obviously qualify for
dual-polarization. It remains to be seen what the FCC will do about
this. Hopefully, they will grow a brain and shift this "un-used"
spectrum to alleviate the very crowded FM band.
I don't know if I should hold my breath or not.?
-mpm