Author Topic: KLAX...Troubleshooting time...All feeders read!  (Read 13526 times)

Offline athaker

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KLAX...Troubleshooting time...All feeders read!
« on: August 06, 2007, 12:54:19 AM »
Esteemed community,

Thanks to Peter, I now have the basic equipment to provide a KLAX feed.

He sent me a discone antenna (a smaller version than the one I see in the radio shack picture, with less "spikes"), an RG-8 cable 50', and a Radio Shack pro-89 hand held scanner.

I bought a long pvc pole (sturdy enough, for now) as a mast to extend just above the roof of my place, and the antenna is mounted on top.

So, I plugged it all together, printed out the KLAX frequencies, and fired the sucker up.  A warmth filled me when immediately a Southwest flight reported himself established on 24R, nearly crystal clear.  To my dismay, however, the tower came in broken. Messing with the squelch, trying the ground and ATIS frequencies, and listening for a while, I concluded that we are faced with our first problem:

I can hear planes, but airport transmissions are not coming in clear.

And so, I appeal to you, the experienced and wise, for possible solutions.

Some of the first things that came to mind are a bigger discone or delving into some of those scanner peripheral.  What do you guys think?



Offline cactushp

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #1 on: August 06, 2007, 02:39:54 AM »
Do you have line of sight?
Scott Mulhollan
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Offline blizzard242

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #2 on: August 06, 2007, 03:07:11 AM »
I have several suggestions, first line of sight (what is between you and the airport), what was the weather (weather conditions can greatly affect radio transmissions it really is a black art, rain and fog will have the most affect along with temp and some unusual atmosphere effects once picked up a plane over 100 miles away). Lastly is your antenna tunable, and do you have it correctly tuned. You get better line of sight to plans so it is a little more forgiving, but the much weaker ground transmissions are much more finicky.

Offline Lezam

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #3 on: August 06, 2007, 09:55:27 AM »
Maybe try to ground your scanner? Get an old telephone cord, or whatever kind you would like and strip the two ends. Connect one end between the scanner and the cable joint, and connect the other end of the cable to something metal like your computer. Make sure the wire is securely touching metal on either side.

Offline KSYR-pjr

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #4 on: August 06, 2007, 11:59:01 AM »
Given that the antenna and cable (but not the scanner) were providing good tower and approach ATC signals for the SYR feed, I would recommend verifying that the antenna cable and antenna itself are not near an electrical source.  Be sure the cable is not running parallel to electrical lines in your house, nor near fluorescent lights.

How about non-home interference?  Any large radio station antennas between you and the airport? 

FYI, the SYR feed is about 9 nm or so from the airport and there is a slight ridge between the airport and the feed's receiving antenna.   I wouldn't call what I have as perfect line of sight to the airport from the receiving antenna's elevation.
Regards, Peter
ATC Feed:  Syracuse (KSYR), NY

Offline KSYR-pjr

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #5 on: August 06, 2007, 12:02:32 PM »
Lastly is your antenna tunable, and do you have it correctly tuned.

As far as I know the antenna in question is not tunable, as it is one of those stock Radio Shack discone antennas.
Regards, Peter
ATC Feed:  Syracuse (KSYR), NY

Offline athaker

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #6 on: August 06, 2007, 01:05:12 PM »
OK, so, here are some answers to your questions:

Line of sight-

I am about 7 miles due south of the approach end of the 24 runways, basically along Sepulveda Blvd.  Unfortunately, there is a house due north of me (my next door neighbors), and it just barely blocks my line to the eastern half of the airport.  The western half, however, is a clear shot, except for a row of trees and probably some 1 story homes that line the southern end of the airport along the Imperial Highway.

As soon as the aircraft on the 25's leave the ground, I can see them, usually well enough to make out the aircraft type.  I cannot directly see any airport structures, and do not know where the airport signals are transmitted from (it's not usually the tower itself, is it?)  I see a tall building and it might be the tower, but i'd think i could tell the shape from far away, and don't have binoculars handy.  It's probably something else.

As far as I can tell, there are no ridges or hills blocking me, since I'm mounting this thing from the balcony railing of the top of a three story townhouse perched on a hill, but my immediate community results in a few homes to block my northeasterly views.

Electronic equipment-
The cable I'm using comes straight down from the mast that extends about 6 feet above a balcony railing, which is directly above my room.  It's not well secured yet, and comes right through my window to a scanner, which will be under my bed.  I think at most, it's a 25 foot run, but I'm using the 50' cable, so the excess is just bundled.  No huge EM fields being created in that short distance, except for a couple of outlets in maybe a 5 foot radius.  Nothing to cause crazy distortion i don't think.

Other EM sources-
I live in the LA area, so the airwaves are basically saturated.  No large radio stations between the airport and I, but definitely some within a 20 mile radius, and many many within a 30 mile radius.  There are also some police and fire dispatch centers nearby.  I thought the other day I might have heard music carrying on the ATIS frequency, so perhaps a filter will clean up the feed a little.

---------

I'll definitely try grounding the thing.  And yes, Peter's antenna is not tunable, and it worked fine for him at KSYR, as he mentioned.  Weather wise it's been overcast the past couple of days but nothing ridiculous.

Keep the tips coming guys.  Thank you, and I'll look into what you've said so far.








Offline BerendBotje1

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #7 on: August 06, 2007, 03:06:10 PM »
Perhaps a wild shot but who knows.  8-)
To eliminate a broken cable during transport or whatever you might try to use the "rubber duck" antenne provided with handheld scanners. I don't know if it came with "the package" but it's worth a try. Get the handheld up to the highest point of your place and listen out the freq's.

Grtz David

Offline KSYR-pjr

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #8 on: August 07, 2007, 12:21:17 PM »
Any luck with this over the last day, Adarsh?   
Regards, Peter
ATC Feed:  Syracuse (KSYR), NY

Offline dave

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #9 on: August 07, 2007, 01:04:01 PM »
Perhaps a wild shot but who knows.  8-)
To eliminate a broken cable during transport or whatever you might try to use the "rubber duck" antenne provided with handheld scanners. I don't know if it came with "the package" but it's worth a try. Get the handheld up to the highest point of your place and listen out the freq's.

Grtz David

Definitely a wild shot.  Those antennas are pretty close to dummy loads.  :-)  Definition of a dummy load is left as an exercise to the reader.

Dave


Offline LAPTOP GAMER

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #10 on: August 07, 2007, 01:20:11 PM »
Dam I hope this works a she is our only shot at KLAX tower right now.

Offline athaker

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #11 on: August 07, 2007, 01:41:45 PM »
Dam I hope this works a she is our only shot at KLAX tower right now.

I hope you meant "as he" laptop gamer...  :-D  j/k

You know, i've been at work since yesterday (24 hour shift), but when I get home tonight i'll muck around with it some.  Only thing I can really do right now is to perhaps reposition my antenna and ground the assembly, so we'll see if that works.

Peter wrapped his equipment nicely so the cable is not damaged or anything like that.


Whats next?
Maybe try to get a notch filter or signal amp?

Offline LAPTOP GAMER

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #12 on: August 07, 2007, 02:33:38 PM »
oops sorry my bad, I meant he.

Offline KMSY

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #13 on: August 07, 2007, 02:37:58 PM »
oops sorry my bad, I meant he.

It made me think for a while, then I figured you were talking about the J-Pole. I call mine Betsy  :wink:.

Offline KSYR-pjr

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #14 on: August 07, 2007, 02:57:26 PM »
It made me think for a while, then I figured you were talking about the J-Pole. I call mine Betsy  :wink:.

LOL!   

I was also struggling with his sentence but ended up giving up.   
Regards, Peter
ATC Feed:  Syracuse (KSYR), NY

Offline athaker

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KLAX ready for more troubleshooting!
« Reply #15 on: August 08, 2007, 05:52:28 PM »
So,

After a few minor antenna changes here is a new finding:

When I lower the squelch, I'm definitely hearing country music on frequency 121.65 (South tower).  It's time to invest in a filter.


From searching around this site now, I think that it looks like the PAR VHF-FM filter has done good things for people in the past.  Unless anyone has anything to say against it, I'm gonna try it.
« Last Edit: August 21, 2007, 02:16:57 AM by athaker »

Offline blizzard242

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #16 on: August 08, 2007, 07:07:08 PM »
You talk about radio station on tower frequency and you get this add.

Offline athaker

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #17 on: August 08, 2007, 07:13:56 PM »
haha.  We're definitely gonna try to purify our "tower air," its true.  Well said Oreck.

Offline KSYR-pjr

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #18 on: August 08, 2007, 07:37:11 PM »
You talk about radio station on tower frequency and you get this add.

Ads?  What ads?   Firefox and AdBlock Plus must be doing something to prevent me from seeing them.  :)  :)

Yes, yes, yes - ad revenue keeps this site going... but so do the feed volunteers, so I have no guilt.
Regards, Peter
ATC Feed:  Syracuse (KSYR), NY

Offline athaker

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #19 on: August 09, 2007, 01:25:45 PM »
NOOOOOOOO!

Universal Radio's VHF-FM filter is on backorder for 2 weeks!  :cry: :cry: :cry:

So according to them, we're looking at about 20 days before I receive the thing...

Talk about it being tough to set up a feed.  Frickin' emotional roller coaster.

Offline Jason

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #20 on: August 09, 2007, 01:30:23 PM »
NOOOOOOOO!

Universal Radio's VHF-FM filter is on backorder for 2 weeks!  :cry: :cry: :cry:

So according to them, we're looking at about 20 days before I receive the thing...

Talk about it being tough to set up a feed.  Frickin' emotional roller coaster.

It's all about the overall experience, my friend.  10 hours in a 105º [tricky] summer attic isn't where I wanted to be either a few years ago when I installed my J-pole and fished the coax down into my room, but it was all out of dedication for this site.  Once you get it going the way you want it to it is surely impressive and something to be proud about.

Offline KSYR-pjr

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #21 on: August 09, 2007, 01:57:34 PM »
Universal Radio's VHF-FM filter is on backorder for 2 weeks!

In this day of the Internet there is only one vendor of that filter?   
Regards, Peter
ATC Feed:  Syracuse (KSYR), NY

Gecko1

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #22 on: August 09, 2007, 02:16:43 PM »
I don't know what you need, but this looks promising.

http://www.scannermaster.com/BPF_AIR_Air_Band_Band_Pass_Filter_p/24-531022.htm

Offline athaker

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #23 on: August 09, 2007, 03:06:04 PM »
universal's the cheapest, but i'm impatient so I ordered it from grove-ent.com.

Looks like all the places, however, don't keep that part in stock, but order it from PAR then forward it to me, according to the lady at grove.  It's supposed to ship to me within 2 days via 2nd day mail so hopefully within the week..

Offline LAPTOP GAMER

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Re: KLAX...Troubleshooting time...All feeders read!
« Reply #24 on: August 09, 2007, 05:16:00 PM »
  We can't wait.
« Last Edit: August 09, 2007, 05:17:39 PM by LAPTOP GAMER »