Converting stock radio antenna to NMO mount - MobileHam Forum at eHam.net

eHam.net Forum : MobileHam : Converting stock radio antenna to NMO mount

Forum Help

1-9 of 9 messages

Page 1 of 1

Converting stock radio antenna to NMO mount	Reply
by KE7SNR on October 1, 2008	Mail this to a friend!
I own a 99 Jeep grand Cherokee that I do not use the FM radio in, thanks to Sirius sat radio. I currently use a FT-60R and a diamond dual-band mag mount. I know this isn't the greatest setup in the world but its what I have. I am looking to install a FT-7800R and a decent antenna. The problem is in order to do that everything I have read is I need to have a NMO mount. After looking for a good location without doing irreversible damage to the Jeep I found a pre-made hole in the form of the stock FM radio antenna location. I am willing to modify this hole if need be but is this a good location? Here is a link to what the antenna mount looks like. http://img367.imageshack.us/img367/5824/1001081309uh9.jpg Thanks 73 KE7SNR

RE: Converting stock radio antenna to NMO mount	Reply
by N4WFB on October 1, 2008	Mail this to a friend!
One problem is that it's at an angle. Of course, if you use a 1/4 wave single band antenna, you can bend the element vertical...I'm not sure if being mounted at an angle would have any detrimental effect, other than aesthetics. If it were me, I'd drill a 3/4" hole in the roof and mount it there. Did it on my old S-10 pickup and my Nissan Pathfinder and never had a leak in 19+ years (combined). About to mount one in the roof of my F150 pickup. IMHO it doesn't hurt resale and as most here will attest, it's a solid, weatherproof mount.

RE: Converting stock radio antenna to NMO mount	Reply
by KE7SNR on October 1, 2008	Mail this to a friend!
The problem with that, other then I do not want to drill a hole in my roof, is that I have a sunroof. The sunroof when retraced would go right into the NMO mount. The section behind where the sunroofs end would be is no longer horizontal so I am not sure if that would work. Thanks

RE: Converting stock radio antenna to NMO mount	Reply
by K0BG on October 1, 2008	Mail this to a friend!
Don't go to all the trouble. Buy an NMO2/70BK with a angled mounting bracket. Unlike the Dodge vehicles, the one on the Jeep has a vertical surface. Mount the antenna towards the rear of the left hood seam, for easy coax routing, and you'll be in like Flynn. And I'd even venture to guess, you won't be able to tell the difference between that location, and the center of the roof. Alan, KØBG www.k0bg.com

RE: Converting stock radio antenna to NMO mount	Reply
by KE7SNR on October 2, 2008	Mail this to a friend!
Thanks Alan. That will work just fine. One question though. I am already using the pass through that you mentioned on the left side of the jeep. It is currently occupied buy some 4ga power wire for my stereo. I know that I would get horrible alternator whine if I ran the coax through there as well. There really is not another pass though in the fire wall, is there some kind of shielding I can wrap or sleeve the coax with that will prevent that whine from happening? Thanks KE7SNR

RE: Converting stock radio antenna to NMO mount	Reply
by K0BG on October 2, 2008	Mail this to a friend!
Wanna bet? Unless you have an open someplace in the coax, there isn't much of a chance to induce enough current into the coax to cause a problem. This assumes you have the coax properly grounded at the mount, which is will be once you get it screwed in (the mount that is). Alan, KØBG www.k0bg.com

RE: Converting stock radio antenna to NMO mount	Reply
by KE7SNR on October 2, 2008	Mail this to a friend!
I was under the impression that just like rca's you do not run coax along the same route as power. Could you explain why a coax is different? Thanks for setting me straight. KE7SNR

Wiring separation problems	Reply
by K0BG on October 4, 2008	Mail this to a friend!
There is a lot of information on the net, and in print, about this subject. Most of it is wrong. If there is no common mode currents on the coax, the chances are very remote that any interference will occur, whether it be ingress or egress. In fact, it is quite common for vehicle manufacturers to run all type of wiring through their respective wiring channels with no extra precautions except for proper insulation. This includes DC wiring, coax for the Navi, XM radio, and AM/FM radio, control and interconnecting busses, etc. The difference is, their neat about it, and they avoid ground loops like the plague. Unfortunately, too many amateurs are sloppy, don't install and wire their gear correctly, and the result is a lot of misinformation. Alan, KØBG www.k0bg.com

RE: Converting stock radio antenna to NMO mount	Reply
by N2IK on October 19, 2008	Mail this to a friend!
Another reason to avoid the stock antenna location is that the access to the underside of the stock radio antenna is pretty restricted. At least it is in my 1996 Grand Cherokee. You also need a special spanner to remove the radio antenna. 73 de Walt N2IK

Page 1 of 1

Next Topic: ft-857 vs ic 706 MkIIG
Previous Topic: hamsticks

Email Subscription
You are not subscribed to this topic.

Check our help page for help using Forum, or send questions, comments, or suggestions to the Forum Manager.