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Old 8-Feb-2011, 7:35 PM   #21
m1kzuua8
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I came across this FM trap from a local RadioShack store:

http://www.radioshack.com/product/in...uctId=10939219


I put it in, and connected the output to the CM-7000.

Nothing showed up for KGO. 0% signal. Don't know if this RadioShack filter is a poor choice. It doesn't help at all.


I'm going to try to move the antenna a bit further to the NW and see if that helps.


I wonder if I should try the Winegard FM trap if it would do a better job than the RadioShack one. If the poor result of the RadioShack FM trap is a good reference, then perhaps I should opt for a more directional outdoor antenna instead? Would HBU33 get KGO, or I'd still need an FM trap w/ it?

Thx.

Last edited by m1kzuua8; 8-Feb-2011 at 7:50 PM.
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Old 8-Feb-2011, 8:32 PM   #22
GroundUrMast
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Please forgive my skepticism of the old antenna and coax, but they are unknown quantities. Rather than buying a second FM-trap, I would buy a new section of RG-6 with connectors, long enough to replace the run up to the antenna. I would not permanently install it necessarily, I would use it to test with the indoor antenna outside, on the roof if necessary. The goal would be to determine if you are able to see any signal from KGO.

The RCA ANT121 dipole rods should be roughly 30" tip to tip for channel 7. The dipole rods should be perpendicular to the line toward KGO's transmitter. You can test with and with out the trap.
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Old 8-Feb-2011, 11:34 PM   #23
m1kzuua8
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So, I placed the the indoor antenna RCA ANT121 outdoor and tried to see what the signal would be.


I had the ANT121 tie rods both set vertically, @ 30° from each other, and had the antenna placed on top of the wooden patio roof (there was no metal cover on the patio roof) one to two feet away from the house's roof, with the front of the antennas facing KGO Ch 7 (see attached photos). I got a previously used 40' RG6 cable (http://awapps.commscope.com/catalog/....aspx?id=34586) used for Dish Network, and connected the ANT121 thru' the RG6 to the CM-7000. I placed the Radio Shack FM trap before the CM-7000. No splitter was used.


I started checking the channels from the top of the channels list on the TVFool chart, and I got all the channels down to KNTV Ch 11 (315°, 50.1 NM). Signal was about 77% for KNTV as indicated by the CM-7000.

I was not able to get any signal from any channels below KNTV Ch 11 on the TVFool chart. I could perhaps get KRON Ch 4.1 (49.9 NM) or KTVU Ch 2.1 (49.5 NM) once or twice. I did get KQED (48.4 NM) periodically--but not reliably.

No KGO obviously from this setup.


So, using the ANT121 placed on the wooden patio roof in the backyard, I was not able to pick up any channels reliably below 50 NM power--whether it was UHF or VHF (KGO). It was almost a steep drop to zero below 50 NM.

Let me know if any of the set up was incorrect.


Notes:
1. One side of the ANT121's tie rod was broken long time ago, and I placed a copper wire to replace the broken tie rod (see 2nd photo). Don't know if this caused any undesireable effects in the result.

2. The old outdoor antenna was mainly losing the reflector piece on one end. Would this have negative influence in picking up KGO Ch 7?
Attached Images
File Type: jpg DSCN2344.JPG (277.4 KB, 558 views)
File Type: jpg DSCN2346.JPG (196.0 KB, 568 views)

Last edited by m1kzuua8; 9-Feb-2011 at 1:14 AM.
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Old 9-Feb-2011, 6:07 AM   #24
m1kzuua8
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Some good news--

I switched back to the existing outdoor antenna as it picked up more UHF channels than the ANT121 placed outdoor.


Odd as it is, I am now able to suddenly pick up KGO from the existing outdoor antenna--w/o using the FM trap. Signal is about 68-76% w/o the splitter. About 50-65% with a 4-way splitter and 25 feet cable from entry of house (from backyard) to the living room.


Two things I've noticed/changed:

1. The last time I adjusted the existing outdoor antenna I did not tighten it to the mast completely. It was a windy day today, and I noticed the antenna was turned clockwise for about 15°.

2. The copper wire @ the connector end in the RG59 cable from the outdoor antenna was dull in color, so I stripped off one inch of the cable and redid the connector to get some good shiny copper wire out for better contact today.


I am going to observe if I can continue to pick up KGO @ this angle for the next few days. Looks like it does require a close tuning to point to KGO right to pick up the signal(!)

And, don't know if that dull copper wire in the connector end also contributed to the problem for KGO before... .


I'm going to try the other room which is further away (40 feet) from entry of house and see if the signal is still good enough.

I re-adjusted the ANT121's angle accordingly to match the existing outdoor antenna's angle and see if that helped--it didn't (perhaps I didn't set up the ANT121 right?)


Good news now anyway! (Perhaps, the wind helps!)

Last edited by m1kzuua8; 9-Feb-2011 at 6:20 AM.
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Old 9-Feb-2011, 6:32 AM   #25
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That's good news...

Copper oxide is a good insulator.

Not a big deal at this point, but another way I could have described the ANT-121 setup would be; Adjust each dipole rod to a length of about 13 to 15 inches each. Lowering each rod to horizontal would be the ideal angle, in theory. With the rods parallel to the ground, that would result in the tip to tip distance being about 30 inches. (Ahhh who am I kidding, that many words makes it a big deal. )

Yeah, the wind is blowing more KGO fumes your way...
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Old 9-Feb-2011, 7:51 AM   #26
m1kzuua8
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Ahh, so for the outdoor setup for ANT121 it's 30" not 30°, my mistake... .

I tried setting length to 15" on both rods and both rods set horizontally (essentially a straight horizontal line). ANT121 picked up several channels more, down to KOFY (20.1, 28.9 NM). It still couldn't pick up KGO (w/ or w/o FM trap). Perhaps haven't got the right angle yet... .


In any case, it has been a good exercise. Now that I've finally got KGO (from the outdoor antenna). ;-)


I'm still keeping an eye on KTLN--it seems the signal is still a bit sporadic--sometimes, it'd drop down to 0% momentarily... .
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Old 10-Feb-2011, 5:26 PM   #27
m1kzuua8
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Now that I can get KGO, the remaining station is KTLN (Ch 68) that I want to get.

KTLN still comes and goes right now. Sometimes I also get pic freeze for KRON (Ch 38) also as the signal sometimes drops to about 20% @ night (don't know why KRON is weaker than KGO--it's @ 49 NM) . I adjusted the antenna a bit but didn't seem to help.


I wonder what the next step would be. HBU33 should help improve in picking up KTLN and KRON (both @ 319°)?


Thx.

Last edited by m1kzuua8; 10-Feb-2011 at 11:42 PM.
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Old 15-Feb-2011, 7:45 PM   #28
m1kzuua8
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I notice that there are diagonal ripples in the TV screen background of my Panasonic Analog TV from the coax output of the CM-7000 converter box.

I switched to use RG6 cable from CM-7000 to my Panasonic Analog TV. It got better, but still some visible ripples in the background.

I wonder if there's any thing I can do to further improve. Is this from some kind of interference from the older RG59 cable from the outdoor antenna (I thought it's digital signal so output video should be immune from interference picked up from the antenna/cable)? Or it's the CM-7000's problem?


I don't see any ripples in the TV screen background when I switched to S-video output from the CM-7000.


Would placing a high-pass filter before going to the TV coax input remove the rippling effect on the TV screen (the CM-7000 outputs on Channel 4)?


Thx.

Last edited by m1kzuua8; 15-Feb-2011 at 10:19 PM.
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Old 17-Feb-2011, 1:46 AM   #29
m1kzuua8
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Also, with my existing outdoor antenna, almost all channels lost half of the signals last night--it was quite cloudy last night and some rain at night. It completely lost Ch 7 for a short while (which had 74% signal strength during a sunny day).


Would HBU33 still hold good w/ keeping strong signals in a cloudy/rainy day?

Last edited by m1kzuua8; 17-Feb-2011 at 7:51 AM.
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Old 17-Feb-2011, 10:03 PM   #30
m1kzuua8
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I think yesterday I lost KGO (Ch 7) because the strong wind caused the antenna to swing left/right for about 10°-15°.

Today it rains more, but there's less wind, so I can still pick up KGO (signal is actually decent)--and even pick up KTLN from time to time (I expected to have lost it completely).

Stations on 10° (I'm point @ 319°) are getting weaker signals now. Pics freeze every min or two along a few of these channels.


Definitely need an antenna with stronger gain that can compensate for loss of signals during a normal rainy day. An antenna w/ shorter boom length will reduce the risk of being blown off-angle easily during a windy day.

Last edited by m1kzuua8; 17-Feb-2011 at 10:05 PM.
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Old 19-Feb-2011, 11:25 PM   #31
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Quote:
Originally Posted by GroundUrMast View Post
Nice antenna... when it had all it's elements. Let's presume it has served well but needs to be retired along with the coax that has been with it in the weather for quite a few years.
...

After having said all that, I think a new antenna and coax will do you wonders.
I flew through SFO on my way home last night... the weather in the Bay Area gets low and wet at times... we were in heavy snow from the Woodside VOR, @ 10,000' all the way till short final at about 1500'. No doubt weather is a factor, but, you need a new antenna and coax.
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