Rear Window Defroster as an antenna

[nkemp]

Has anyone used the rear window defroster as an antenna? The two issues I can imagine is that it is very close to the engine(electrical noise) and that it is shielded by the body. None-the-less, anybody have any luck?

Nick

[nkemp]

I've seen this done two ways on other cars.

WAY1: Cut the traces so that they are used as an antenna and not used to defrost

WAY2: Uses the traces as both a defroster and an antenna. The 97 Buick Skylark offered this as an option and here is a link to a guy that made his own antenna to the defroster grid. http://www.ek9.org/forum/resource-area/31048-diy-internal-home-made-car-antenna.html


I have the windshield antenna version and it works OK. But I know there is a rock laying out there somewhere waiting for my glass to get in its way.

[Farrar]

My 1998 Chrysler Concorde used the rear window resistor as an antenna and it worked fantastically. I would maybe install a choke on it somewhere if the signal is noisy, but unless you listen to a lot of AM radio I don't think the engine electrics would dirty up the signal that much.

Farrar

[aludden]

Thanks for the link to the antenna article! Has anyone tried this?
Thanks!
Alex

[Josh]

Attempting this tonight. Will report back.

[nkemp]

I have the windshield antenna version and it works OK. But I know there is a rock laying out there somewhere waiting for my glass to get in its way.


On the way to DCS 14, while driving the interstate, in slowmo I watched that rock fly right into the center of my D's windshield. It made a good thud but no crack and very little mark. FWIW the rock then flew up into the air and hit the car's window behind me. That car was one of our local owner's that went to DCS in a rental car. And yes, it did more damage to that windshield than to mine.

Josh

Let us know what technique you use and we do look forward to how well it works ... or not. Good luck. Nick

[Josh]

On the way to DCS 14, while driving the interstate, in slowmo I watched that rock fly right into the center of my D's windshield. It made a good thud but no crack and very little mark. FWIW the rock then flew up into the air and hit the car's window behind me. That car was one of our local owner's that went to DCS in a rental car. And yes, it did more damage to that windshield than to mine.

Josh

Let us know what technique you use and we do look forward to how well it works ... or not. Good luck. Nick

Lol, I remember hearing about that!

I do not have my defogger hooked up so i will not do the bypass. but it can be done both ways. You can use a relay instead of a capacitor like so:

85 and 87 would be the power to the window from the defogger circuit. 30 would be the window itself. The ground side of the window would email attached.

30172

I am going to unplug the power side of the defogger and attach the antenna core/primary directly to that. The sheild will then be grounded if need be, but i dont see the need as its already grounded on the radio end. Ill experiment both ways.

[Josh]

Here are my trials. Worked out very well!


https://www.youtube.com/watch?v=Ae1OxTyBIYc

[Tomcio]

I do not have my defogger hooked up so i will not do the bypass. but it can be done both ways. You can use a relay instead of a capacitor like so:

85 and 87 would be the power to the window from the defogger circuit. 30 would be the window itself.

If you use a relay the antenna will work only when the defogger is not used. Once you turn it on you loose your reception. The capacitor is there so you can have good reception regardless if the defogger is powered or not. It separates the DC current from going into the radio receiver and blocking all reception and possibly releasing some magic smoke. I would go with the separating capacitor so the antenna works even when the defogger is on.

[nkemp]

Sounds good Josh! Have you tried it driving? I'd be interested to hear if it picks up much engine noise.

Not to argue with Tomcio ...but has anyone ever used the rear defogger to defog/deice the rear window? Based on where the rear windo is, it seems really hard for it to fog or ice.

[SS Spoiler]

Nick, the majority of cars are put away during cold weather. Winter is when big De projects are done. I use the defrost switch to control my lighted
bumper letters.

Paul Cerny #2691
Kalispell, MT

[NightFlyer]

Not to argue with Tomcio ...but has anyone ever used the rear defogger to defog/deice the rear window? Based on where the rear windo is, it seems really hard for it to fog or ice.

Only once, and that was 12 years ago when I had the car at Mount Rushmore. It was raining and windier than all get up when I parked the car in the hotel parking lot, and then it flash froze overnight (this was in late June / early July). I didn't have a window scraper with me. I had the radio and rear defrost on while waiting for the girlfriend to use the bathroom, using my driver's license to clear the windshield and side windows, but didn't start the engine until she was ready to depart. It worked well and cleared the window in a few minutes.

[jwrayth]

I have used mine more than once. Though I am in the UK, so climate is a bit different. I have the heated wing-mirrors that are triggered on this circuit too.

I'm looking to replace my rear antenna, so I may just add this to my sound-system improvements planned for this winter!

[Josh]

no noise when driving, works great! If you unground the defogger there is alot of noise, driving or parked. But just with AM frequencies. It is critical that one side of the defogger is grounded and the other is hooked to the antenna.

That is correct the antenna wouldn't work when defogging. the cap would work fine. But honestly i dont see the need for this car to have a rear defogger, as previously mentioned who is driving their car in the winter. I think the heat from the engine would do a good job of defogging the window anyway.

[Tomcio]

Sounds good Josh! Have you tried it driving? I'd be interested to hear if it picks up much engine noise.

Not to argue with Tomcio ...but has anyone ever used the rear defogger to defog/deice the rear window? Based on where the rear windo is, it seems really hard for it to fog or ice.

Naah, this isn't arguing ;)
I was just stating a fact that if you use a relay you will have either defrost or antenna and not both. With the separating capacitor you can have both.
I have owned a DeLorean since 1998 and I've used the defroster once. I was at my girlfriend once and the D was parked outside all night long. The weather was cool but nice when I arrived but in the morning I realized that it's been snowing all night long. It was thick wet snow that then froze solid as it cleared out and the temperature dropped to well below freezing during the day. By the time I was ready to head home my D was a solid block of ice and snow including the rear window. I couldn't even lift the louvers to clear it out! So, I started the engine and switched the defroster on for the first time ever. It worked great and.... I have never used it again. Still, since it's there I want to keep it operational. Who knows, maybe the next ice age will come and I'll need it again... someday.
I love the idea of using the defroster as a hidden antenna and I will use it on my car but I will keep the defroster function as well.

[vps3922]

Naah, this isn't arguing ;)
By the time I was ready to head home my D was a solid block of ice and snow including the rear window. I couldn't even lift the louvers to clear it out!

C'mon, you just returned from a trip to the future. :wink: