AVS Forum banner
Status
Not open for further replies.
1 - 20 of 37 Posts

·
Banned
Joined
·
9,999 Posts
Discussion Starter · #1 ·
Hello All,


I just picked up the Channel master 4228 antenna. According to the manufacturer's website, a pre-galvanized mask is included. I am not entirely sure what CM means by this as what I interpret as a 'mast' was not in the box.


Reading the installation instructions shows included clamps that appear to be designed for a non-tubular mast. Unfortunately, all the local home improvement stores sell tubular masts, and these included clamps just are not going to work.


I sent an email (and waiting on a reply, of course) to CM for clarification on 'pre-galvanized mast', and suggestions they may have for using an appropriate mast. I am trying to rig this antenna up with temporary cabling in order to watch the UF-UT game tomorrow on CBS and in HDTV (if its gonna be in HD).


Anyone have any suggestions for a mast? And no, I've never installed an antenna before so I think I'll be spending the day learning how to install and aligning the antenna.
 

·
Registered
Joined
·
286 Posts
I think you'll be fine with a tubular mast...those corners on the brackets are just to make them grab the mast better.


Don't think your game is going to be HD...IIRC Georgia/LSU is the HD game tomorrow.
 

·
Banned
Joined
·
9,999 Posts
Discussion Starter · #3 ·
Geno, anyway for me to better-determine if the UF-UT game is in HD? BTW, I agree about those brackets. My latest problem is trying to mount a mast in my attic. I have no way of mounting the top of any mast as the attic's ceiling if taller than even I originally though--must go up a good 18-20 feet along the centerline.
 

·
Registered
Joined
·
286 Posts
CBS College Football schedule:
http://www.sportsline.com/u/cbs/sche...l_football.htm

(Sorry about your luck)


ChannelMaster (and many others) sell tripods made to hold masts...you could lay a piece of particleboard flat and mount the tripod on that. Also, someone else in here had an excellent installation of an attic rotor/antenna installation that was fantastic....I'll see if I can find it.
 

·
Registered
Joined
·
1,129 Posts
Just go get a piece of 1" or 1.5" rigid PVC (8' or 10' length). You can use that for a temporary mast inside your attic. If there are any cross-braces across the rafters (there ought to be some), just attach the PVC to that, hang the rest of the PVC *down* and clamp the antenna onto that.


This ws my 'temporary' setup from six months ago....its still there working fine.
 

·
Registered
Joined
·
941 Posts
Although I didn't think it was going to work at first, I was able to use the brackets included with a 4228 to mount my antenna to a mast. I had some 10' sections of 1.25" electrical conduit laying around and just mount the antenna to that. Had to press the mast against the antenna in order to get the nuts to grip, but it went together OK. It would have been much easier if the U-bolts had been a .25" longer!
 

·
Banned
Joined
·
9,999 Posts
Discussion Starter · #9 ·
My wife could stand on my shoulders and raise her arms and still not be able to touch the cross-bracing you're thinking about. Its too hot up there at the moment so it'll have to wait until the morning.


I am think a small steel plate with the corners punched open for screen. In the center of this plate is a collar that has threads on the inside to receive a threaded pipe. I do not know the formal name of this plate (they exist) and I'm thinking of bolting one to a piece of 3/4" plywood as the base, and a 8' threaded pipe as the mast.


For some entertainment on how to take lousy pictures with a POS camera ...

http://home.speedfactory.net/wanman/OTA/P0000759.JPG
http://home.speedfactory.net/wanman/OTA/P0000760.JPG
http://home.speedfactory.net/wanman/OTA/P0000761.JPG

The highest flex-ducts you see in the last photo ar at 6' elevation and about 1/3 the maximum height on the attic's centerline.
 

·
Registered
Joined
·
1,129 Posts
uh....I see some vertical posts in those pictures. If you want something temporary just to test, you can just lean the antenna against the posts or even attach the PVC I suggested to the posts....


...also....you can just go to where the rafters are only 5-6 feet high (they are angled, right) and attach the pvc there...


...remember this is just temporary, right. And you;ll still eventually have to move around and find the 'sweet spot' where the OTA signal is strongest.


This is not a quick setup job...invest some time.
 

·
Banned
Joined
·
9,999 Posts
Discussion Starter · #11 ·
Those 'vertical' posts are beteen 15-30º off the vertical. The rafters I think you are talking about are visible in the second photo on the right edge. They are about 6', yes.


BTW, anyone know how to find the 'sweet spot's signal' on a SIR-TS160?
 

·
Registered
Joined
·
1,129 Posts
...even if the posts are off vertical, just anchor the pvc using 1 screw and a washer....don't tighten it until it is vertical....that's what I did for my original tests....but attached it to a rafter.


regarding finding the sweet spot.....its best to have 2 people with frs radios or cellphones....one person downstairs watching the meter on the ts160...another person upstairs (attic or roof) who moves around the antenna....just be sure to check antennaweb.org or 2150.com/broadcast to find the azimuth (heading) where you should point your antenna (to get a strong signal). keep in mind that unless all dtv broadcasters in your area transmit from the same tower, you will likely not get all stations from one direction. the 4228 is extremely directional, so it needs to be pointed in the right direction. once you have the approximate right direction, if the signal seems weak, hold the azimuth direction and walk around the attic (hopefully theres a floor up there) until the signal read strongest on the meter.


signals are usually strongest when the antenna is placed just inside the outside wall...assuming of course that you don't have stucco siding with a wire mesh imbedded inside (this would kill much of the signal in the attic).


for me, i've got standard stick construction, plywood sheathing, and vinyl siding. my signals are greatest just inside the southwest facing wall of my house (that's the direction of the transmitters in Philadelphia).


Good Luck.
 

·
Banned
Joined
·
9,999 Posts
Discussion Starter · #13 ·
Steve, tere are no floors in my attic. I live in the south and this is southern construction. Attics are a non-functional item to southern builders. Look closely at those first two pictures and you will see blown fiberglass insulation all over the place. Nice huh?


BTW, the www.2150.com/broadcast website is a nice reference.
 

·
Registered
Joined
·
1,129 Posts
So its seems you'll have to have good balance and step v-e-r-y carefully while trying to find the sweet spot.:D


Don't worry.....northern builders do the same thing with attics.....they leave it to the residents to do anything sensible with them. BTW...one of my first projects in this house 13 years ago was to install flooring in the main attic. And I only fell thru the ceiling once while doing it, too.:eek:


Yes, 2150.com/broadcast is very nice....I can't take any credit....it was put together by another member of the AVSforum....doug swallow. He did a great job with it!
 

·
Banned
Joined
·
9,999 Posts
Discussion Starter · #15 ·
Heh, the county decided that HVAC (AC/Furnace) has to be on the center of the center-line of the building. This, as the photo shows, offers the obstacle of being right in the way as soon as you get into the attic, with all kinds of good stuff getting in your way to offer the best opportunity to test the 230-pound wanman through drywall, and potentially down the 2-story foyer.
 

·
Banned
Joined
·
9,999 Posts
Discussion Starter · #16 ·
BTW, how far away do I need to be away from that HVAC? I can only imagine what kind of EM field it puts out due to the blower year round, and the heating element in the Winter.


It seems the majority of my stations are at the 250-245º direction, and 23-34 miles away (as the bird flies, of course). Steve, exactly how directional am I going to need to be with the 4228?
 

·
Registered
Joined
·
181 Posts
A question about wiring the 4228. I am using 300-ohm twinlead because that is the input for the CM amp I have on the mast. Initially I had the twinlead routed behind the 4228, thru the antenna's mesh and down. But I read somewhere that twinlead loses a lot of signal as it goes thru the mesh, so now I run it straight down, between the bowties, which doesn't seem all that much better. Would I be better off using two matching transformers and 75-ohm cable?
 

·
Registered
Joined
·
941 Posts
I'm getting excellent results using 300ohm twinlead (about 3' long) down the front of a 4228 to my pre-amp. I also tried one matching transformer at the antenna (pre-amp will take 75-ohn input), but I think I get better performance with the 300-ohm. Consider also, that each balum will have .5-2dB signal loss, compared to the twinlead.


WanMan


Seems like I've read that it is good to keep the antenna at least one wavelength away from anything that can reflect the signal, and metal HVAC ductwork can reflect the signal. But then, it's hard to follow that rule in an attic.
 

·
Banned
Joined
·
9,999 Posts
Discussion Starter · #19 ·
Neil, you are correct. Well, I just found a spot to drop the antenna at. I used a section of 3/4" plywood for a base, screwed a flange-plate for a threaded 3/4" steel pipe, to which I mounted a 3' section of 3/4" steel pipe.


I then took a 4' section of 3/4" steel pipe and mounted the 4228 to it, and threaded everything together. Seems fine. I now need to get my bearings. I need to point the thing around 240-245º, but I have no compass. Yeah, I know the sun rises in the East and sets in the West, hehe.


I need to hurry up this job as my attic ladder is about at it end.
 

·
Registered
Joined
·
1,280 Posts
FYI- The 4228 doesn't care about anything located behind the mesh screen. Don't be too concerned about keeping its back side far away from things.
 
1 - 20 of 37 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Status
Not open for further replies.
Top