The Subaru SVX World Network   SVX Network Forums
Live Chat!
SVX or Subaru Links
Old Lockers
Photo Post
How-To Documents
Message Archive
SVX Shop Search
IRC users:

Go Back   The Subaru SVX World Network > SVX Main Forums > Technical Q & A

Reply
 
Thread Tools Display Modes
  #1  
Old 04-23-2009, 11:51 PM
Black88GTA's Avatar
Black88GTA Black88GTA is offline
look like a leprechaun to me
 
Join Date: Jan 2009
Location: Huntington, NY
Posts: 249
Does the mast antenna ever go bad? Reception problems.

Not the mechanical parts (like the motor or mast, etc). I'm concerned with reception.

Some backstory...when I got my car, the power antenna was trashed, so it was replaced with a used part. The used unit still didn't work at first, because the power antenna lead had been cut behind the radio (lame / incomplete wiring job by the previous owner). So, I fixed this, and now the motor was running, but the mast wouldn't extend / retract all the way. After polishing the mast (huh huh ) and tweaking it section by section, I got it working perfectly (well, mechanically at least).

So now it's connected properly and extends / retracts fully when it is supposed to, but the reception is terrible. It pulls in plenty of stations, although none of them really well - even local stations are staticky and fuzz out at times. I am running off of the mast alone - the glass antenna is currently disconnected. I figured this wouldn't be too big a deal, since I've owned plenty of cars with only a mast antenna that get great reception, even from distant stations. The head unit (if it matters) is a Dual XDV8525.

So what gives? Is there something in the power antenna that can go bad and screw up reception? Or is it something to do with the fact that the glass antenna is now out of the loop? I am in the process of modifying a standard 1M ==> 2F Y-adapter that will allow me to plug both antennas into the jack on the back of the deck, but I don't think I should have to do this in order to get acceptable reception.

Anyone have similar issues that they fixed? Do I have to get a replacement power antenna unit, or is there something in there (a wire, etc) that I can fix if I remove it and crack it open? Or is this just the way it is?
__________________
Ebony/Gray '92 LS-L, @123k - bought 01/17/2010, parked for 10 years. Getting back on the road.
Reply With Quote
  #2  
Old 04-24-2009, 08:23 AM
SoCal LS-L's Avatar
SoCal LS-L SoCal LS-L is offline
Avalanche Alcyoneer
Subaru Silver Contributor
 
Join Date: Sep 2008
Location: Reno, NV
Posts: 2,130
Registered SVX
Re: Does the mast antenna ever go bad? Reception problems.

Quote:
Originally Posted by Black88GTA View Post
Not the mechanical parts (like the motor or mast, etc). I'm concerned with reception.

Some backstory...when I got my car, the power antenna was trashed, so it was replaced with a used part. The used unit still didn't work at first, because the power antenna lead had been cut behind the radio (lame / incomplete wiring job by the previous owner). So, I fixed this, and now the motor was running, but the mast wouldn't extend / retract all the way. After polishing the mast (huh huh ) and tweaking it section by section, I got it working perfectly (well, mechanically at least).

So now it's connected properly and extends / retracts fully when it is supposed to, but the reception is terrible. It pulls in plenty of stations, although none of them really well - even local stations are staticky and fuzz out at times. I am running off of the mast alone - the glass antenna is currently disconnected. I figured this wouldn't be too big a deal, since I've owned plenty of cars with only a mast antenna that get great reception, even from distant stations. The head unit (if it matters) is a Dual XDV8525.

So what gives? Is there something in the power antenna that can go bad and screw up reception? Or is it something to do with the fact that the glass antenna is now out of the loop? I am in the process of modifying a standard 1M ==> 2F Y-adapter that will allow me to plug both antennas into the jack on the back of the deck, but I don't think I should have to do this in order to get acceptable reception.

Anyone have similar issues that they fixed? Do I have to get a replacement power antenna unit, or is there something in there (a wire, etc) that I can fix if I remove it and crack it open? Or is this just the way it is?
I wouldnt use the Y adapter, that will just make things worse. It sounds like maybe the sections of the mast might not connect well, making it a smaller antenna so to speak. This is assuming that you have checked and double checked your hard connections at the deck, the extension connection by the transmission hump, and at the antenna itself. I pulled the guts out of my old power motor (broke inside) and just use the mast permanently extended, works great even out here in the cuts. Maybe you polished the mast one too many times (yuk yuk yuk)
__________________
Chris

"A person convinced against their will, is of the same opinion still"

New?? Find the downloadable SVX Online Service Manual Here
RECOMMENDED READING for newer SVX owners Here some cool info if not fully accurate.
Reply With Quote
  #3  
Old 04-24-2009, 08:45 AM
BoxerFanatic's Avatar
BoxerFanatic BoxerFanatic is offline
Registered User
 
Join Date: Mar 2009
Location: Central Iowa, United States
Posts: 941
Re: Does the mast antenna ever go bad? Reception problems.

I just bought one of these, from an ebay sale from the company listed here... (buy only, not an auction... but not listed at the moment.)

http://www.locustom.com/shark2_kit.htm



This link actually shows some installed pics at the bottom of the page...
http://www.locustom.com/antennas.htm

The antenna itself is made by Fuba, evidently an OEM distributor to many car manufacturers.

I am going to try to install it on my Miata this weekend, to replace a power antenna that got bent, and won't fully retract, and stands about the same height anyway. I figure the power would be better used for amplification, and the fixed antenna is less likely to get bent again.

Something like that might or might not fit an SVX... and the amplification might help the static issue.

But agreed, Y-connecting two antennas will probably not do beneficial things for the tuned length... Better to run one good antenna, if the stereo is not capable of diversity tuning, with two individual inputs.

Or, for the cheap, you could put a plastic body plug in the mast antenna hole, and just hook up the glass antenna instead, as the only antenna.

Last edited by BoxerFanatic; 04-24-2009 at 08:55 AM.
Reply With Quote
  #4  
Old 04-24-2009, 10:49 AM
SVXdc's Avatar
SVXdc SVXdc is offline
Radio wiring harness guru
Subaru Gold Contributor
 
Join Date: Oct 2002
Location: Atlanta, GA
Posts: 615
Significant Technical Input Registered SVX
Re: Does the mast antenna ever go bad? Reception problems.

I agree on not using a Y adapter — combining the two antennas in parallel will cause an impedance mis-match. You may get better reception, but only because the motorized antenna is so crappy. I think you'll find that you'd get even better reception with the window antenna alone.

It sounds like you're not getting good continuity out to even the lowest segment of the motor antenna. Unplug the coax antenna cable at both ends (side of transmission hump and base of antenna motor) and use an ohm meter to check the car's cable. While you're at it, go ahead and check from antenna jack at the base of the motor to the first segment.

The antenna installation instructions are in the How-To section, here:
http://www.subaru-svx.net/photos/files/How-To/28253.pdf
(whoever wrote that guide did an excellent job!)

The bottom-most portion of the mast is hidden until you disassemble it. Perhaps cleaning that will help.

Since you'll have everything disassembled anyway, you should also clean the inside of the tube that the coax attaches to. Only clean in one direction inside the tube. See step 12 of that guide!

Of course, the problem could be in your aftermarket radio. I'd try temporarily testing the radio with another antenna, and another car radio with the SVX's motor antenna.
__________________
David C.
1996 Laguna Blue Pearl SVX L AWD
See my home page for SVX radio install/removal instructions and wiring harnesses

Last edited by SVXdc; 04-24-2009 at 10:54 AM.
Reply With Quote
  #5  
Old 04-24-2009, 05:15 PM
Black88GTA's Avatar
Black88GTA Black88GTA is offline
look like a leprechaun to me
 
Join Date: Jan 2009
Location: Huntington, NY
Posts: 249
Re: Does the mast antenna ever go bad? Reception problems.

Thanks for the help, all...maybe I'll scrap the Y-adapter idea, since it seems that isn't going to work as intended. I figured combining a (possibly incomplete) signal from both would patch the missing bits in and give the most "complete" signal to the deck. I don't really want to do a fixed rubber antenna, just don't like the look much myself...if I can't get the power one working right, I'll probably just unplug it and run with the glass one, even though I wasn't too impressed with that one either when I had it hooked up.

SVXdc, thanks for the install link...I'll check the cords / connections first, then start disassembling if that doesn't work. How would I check the cable running from the front of the car to the trunk using a hand-held ohmmeter without removing it? Long ass leads with alligator clips? Would I just be checking continuity, or resistance? Outer connector, or center pin (or both)? And if I'm checking resistance, what values should I expect to see if it is normal?

Sorry for all the questions...
__________________
Ebony/Gray '92 LS-L, @123k - bought 01/17/2010, parked for 10 years. Getting back on the road.
Reply With Quote
  #6  
Old 04-24-2009, 06:15 PM
Trevor's Avatar
Trevor Trevor is offline
Registered User
 
Join Date: Feb 2002
Location: Auckland, New Zealand
Posts: 5,223
Registered SVX
Re: Does the mast antenna ever go bad? Reception problems.

I gather you have made a joint in the cable as a means of repair. Have you taken into account that there is an inner conductor insulated from an outer shielding sleeve, both requiring separate connection, as well as inner and outer insulation? Not a simple job but it can be done.
__________________
Trevor, New Zealand.

As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit!
Reply With Quote
  #7  
Old 04-24-2009, 07:39 PM
SoCal LS-L's Avatar
SoCal LS-L SoCal LS-L is offline
Avalanche Alcyoneer
Subaru Silver Contributor
 
Join Date: Sep 2008
Location: Reno, NV
Posts: 2,130
Registered SVX
Re: Does the mast antenna ever go bad? Reception problems.

Id say forget about the glass antenna, when I had it hooked up alone my reception was only marginal. Its meant to be just a backup in case your car is in a bad signal position under a bridge or something like that where the main antenna is blocked. After I fixed the mast to my main and reconnected, my reception was much much better. If you cant get reception with the one you have, and dont want to pay bank for a replacement, id just go with a regular fixed mount.
__________________
Chris

"A person convinced against their will, is of the same opinion still"

New?? Find the downloadable SVX Online Service Manual Here
RECOMMENDED READING for newer SVX owners Here some cool info if not fully accurate.
Reply With Quote
  #8  
Old 04-24-2009, 08:46 PM
Black88GTA's Avatar
Black88GTA Black88GTA is offline
look like a leprechaun to me
 
Join Date: Jan 2009
Location: Huntington, NY
Posts: 249
Re: Does the mast antenna ever go bad? Reception problems.

Quote:
Originally Posted by Trevor View Post
I gather you have made a joint in the cable as a means of repair. Have you taken into account that there is an inner conductor insulated from an outer shielding sleeve, both requiring separate connection, as well as inner and outer insulation? Not a simple job but it can be done.
Actually, no. No joints / cuts in the cable have been made yet. Currently, the deck is plugged in to the mast antenna only, and the glass is unhooked. I actually have a Y-adapter and a male antenna plug that I purchased. My plan was to cut one of the female sockets from the Y-adapter and install the male plug end in its place to connect with the glass antenna, and use the remaining female socket to plug in the mast.

Quote:
Originally Posted by SoCal LS-L View Post
Id say forget about the glass antenna, when I had it hooked up alone my reception was only marginal. Its meant to be just a backup in case your car is in a bad signal position under a bridge or something like that where the main antenna is blocked. After I fixed the mast to my main and reconnected, my reception was much much better. If you cant get reception with the one you have, and dont want to pay bank for a replacement, id just go with a regular fixed mount.
That was my thoughts on the glass one too...really not that great, but it was lots better than the mast when I had it hooked up by itself. I'm going to do all I can to get the mast working properly though before scrapping it.
__________________
Ebony/Gray '92 LS-L, @123k - bought 01/17/2010, parked for 10 years. Getting back on the road.
Reply With Quote
  #9  
Old 04-25-2009, 12:06 AM
SVXdc's Avatar
SVXdc SVXdc is offline
Radio wiring harness guru
Subaru Gold Contributor
 
Join Date: Oct 2002
Location: Atlanta, GA
Posts: 615
Significant Technical Input Registered SVX
Re: Does the mast antenna ever go bad? Reception problems.

Quote:
Originally Posted by Black88GTA View Post
How would I check the cable running from the front of the car to the trunk using a hand-held ohmmeter without removing it? Long ass leads with alligator clips? Would I just be checking continuity, or resistance? Outer connector, or center pin (or both)? And if I'm checking resistance, what values should I expect to see if it is normal?
Yes, extend your meter's leads with a long (good) wire. If you can, zero the meter with just the long wire. Then you'll be measuring the resistance of the coax. If you can't zero, subtract the value you get with just the long wire.

You're mainly looking for good continuity, but if the resistance is more than a few ohms, I'd start being concerned about the condition of the coax cable. The center conductor end-to-end is the most important, but no reason not to check the shield end-to-end while you're at it. Also check the resistance between the two (should be infinity).

I'd be interested to hear what you find.

Trevor, both ends of the coax cable for the SVX's motorized antenna have standard Motorola connectors, so it will be easy to clip or hold an alligator clip, wire, or test lead probe at each end.
__________________
David C.
1996 Laguna Blue Pearl SVX L AWD
See my home page for SVX radio install/removal instructions and wiring harnesses
Reply With Quote
  #10  
Old 05-12-2009, 07:38 PM
Black88GTA's Avatar
Black88GTA Black88GTA is offline
look like a leprechaun to me
 
Join Date: Jan 2009
Location: Huntington, NY
Posts: 249
Re: Does the mast antenna ever go bad? Reception problems.

So, a small update...I finally tackled this tonight. I messed with it a little bit last week, but didn't get much accomplished. It now pulls in stations I didn't even know existed

The first thing I did was check the wire. It tested out OK, but not trusting my measurements, I tried replacing the cable anyway. It was easy to just run a wire from the trunk to the front for testing purposes, so I hoped I'd get lucky and that's all it was. Unfortunately, this made it worse (if anything).

Tonight, I pulled the antenna assembly, took the whole thing apart, cleaned and oiled it, and put it back together using the guide found in the how-to documents here. The mast was dirty and sticky, so I cleaned all that crap off with some goo-gone spray I had here, until it was moving freely. It wasn't too bad before, but was really smooth after I cleaned it. I also cleaned the dirt off of the inner cable while I was at it, and all of the other parts as well.

For oil, I used some standard 10w-30 I had here. Probably not the most ideal thing for this, but it was all I had around, and it seemed to work ok. To get it up inside the mast, I stuck the bottom of it in the oil, and extended / retracted it quickly, so the oil "pumped" up to the top of the mast from the inside. It got a bit messy. After that, I removed the whole assembly from the oil, and extended / retracted it until no more excess oil came out of it.

While it was all apart, I also used a piece of stiff coat hanger to "pry" the little contact tab for the antenna lead (inside the housing) out a little bit, so that it would make a more solid contact with the mast assembly.

Once it was all back together, I installed it and tested it. It works great now! Before, it would make a loud whirring noise when extending / retracting, now it's nearly silent. And of course, the reception has improved 1000x over what it was.

Thanks to all who helped
__________________
Ebony/Gray '92 LS-L, @123k - bought 01/17/2010, parked for 10 years. Getting back on the road.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 12:14 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
© 2001-2015 SVX World Network
(208)-906-1122