Power antenna electrics

[sblake01]

Check these out. The first ad says "ZX" but that's a up to Aug 73 switch and it will operate a 78 antenna and the antenna is for a 76 but could work in a 78.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=019&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=290054800338&rd=1&rd=1

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=006&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=160055395571&rd=1&rd=1

[EScanlon]

I'm going to try to address the various issues as briefly as I can...so bear with me, as verbose as I can be, that's not easy.

I know most of you already know this, and repeating it may be obnoxious, but bear with me.

The OEM Switch is a Momentary-SPDT, Single Pole (meaning ONE wire) Double Throw (meaning TWO possible connections). This means that it can either connect circuit A or circuit B to the incoming wire. In the Early Z's, that means it either sends 12+ DC it receives from the Blue wire through EITHER the Blue/White OR the Blue/Red. Momentary means that it doesn't "click" and stay connected, it's spring loaded and YOU must continue to keep it connected for as long as you want it to operate.

The OEM Antenna has 2 wires comnig out of the motor housing. EITHER of those wires can receive 12+ DC. Depending on which wire is energized, the motor will spin in that direction. The third connection it has is GROUND to complete the circuit.

The OEM Antenna is considered a Semi-Automatic antenna because while it does go up / down electrically, it requires you to close the switch and actuate it either up or down. Additionally, IIRC, it does not have limit stops that will disconnect the wiring once it is fully up /down. My replacement came from the dealer, and it will continue to whirr and click as long as I keep the button pressed.

Today's Semi-Automatic Antenna, also has 4 wires coming out of the motor body, but DOES NOT REQUIRE A GROUND. That's because the M-DPDT switch you get with it does the power inverting that the antenna needs to operate up or down.

A FULLY Automatic antenna not only goes up and down electrically, it SENSES when to go up / down AND it has limit stops at the extremes of it's travel. It connects directly to the radio's power on button. When you turn on the radio, the antenna senses it and then extends itself to the FULL Up mode. Turn off the radio and it reverses operation and retracts completely. There is NO middle ground in it's operation. Full Up/Down, that is the operation. Typically, these antennas have 3 wires. Ground, Constant 12+ DC and Radio Power 12+.

For the record, a MANUAL Antenna is one that must be extended and retracted via HUMAN power.

The Fully Automatic needs a Momentary-DPDT switch in order to operate AS IF it were an Early Z's OEM Antenna. By proper wiring you turn off ALL the power or only PART of the power in order to "fool" it into stopping partly extended/retracted.

I've explained the switch wiring before in other posts.

HTH

E

[TomoHawk]

It's good to repeat the explanation. Each time it gets refined even better. And it is very important to use a momentary SPDT switch. The only problem with getting one through eBay is that you don't know for sure if that's what it is, so I'm also looking at generic rocker switches through Mouser Eletronics (unless I decide to trek across town to the electronic surplus store.) I'm pretty sure that the 70s & 80s antenna switches were mostly the momentary type. It might even be possible to use the swich for a power window or door lock. I'm not up to that part yet, and it's not even December...

thx

[EScanlon]

Tomohawk:

The type of switch you use is dependent on the type of antenna you have.

E

[TomoHawk]

Mine needs to be a SPDT momentary like I've been saying.

[sblake01]

Actually, the stock switch is a DPDT rocker switch (momentary on-off-momentary on). If you intend to use the original antenna, that's what you'll need. Rather than trying to find a switch that will work, and attempting to wire it so that it will work in your car, possibly frying something in the processs, why not use an original type switch like the one I linked to on eBay? By what you've posted so far in this thread, I really don't think you know what type of switch the original one is.

[TomoHawk]

Look at Page BE-74 in the FSM, where it shows details of the radio parts, as well as a diagram of the antenna switch connector and the connections the switch makes to operate the antenna. You will see that the switch is a SPDT type (momentary, of course.) Otherwise, how could you hook up a DPDT switch with only 3 wires? 240Z switch maybe? I would agree that you would need a DPDT switch to operate an ordinary semi-automatic type power antenna.

thx

[sblake01]

Sorry, I'm actually looking at an 810 switch which has four wires.

[TomoHawk]

You are just too enthusiastic, Stephen. :cheeky:

[TomoHawk]

Another reason why I'm thinking of using a (generic) switch is so I can use that one unused plate next to the hazard switch. Maybe there's a rocker switch that will fit in one of the outlines, like Enrique mentioned. Too bad Radio Shack doesn't cary them tho. Maybe some other place.

Suggestion (style D or F): http://www.mouser.com/catalog/628/1350.PDF

[TomoHawk]

OK, I got my "fully-automatic" antenna off eBay (AntennaX brand) and I looked inside the control box. There's a relay, and a geared switch for the ground leg. With the voltmeter, I poked around what's inside while the motor was on to see what the deal is, and still haven't figured that part out (yet.) It's a plain old DC motor, so maybe you can rewire the relay to make it work differently.

It is possible to hook up a full-auto antenna to go up & down as you want, like an oem antenna does. You need a DPDT, center off, momentary switch to do it.

Power chart:

. . . . . Up . Dn . Off

Sens. ..X . . O . . O

+12V. . X . . X . . O

Sens: antenna sensor wire

+12V: constant power ( from Ign or ACC circuit)

So, with some fancy jumpers on a DPDT switch, and the stock wires, you can control your antenna, just not with the oem SPDT switch. eBay has some nice antenna switches from Mercedes, et al, but since I don't know what the pin-outs are, I don't really want to waste money on that.

HTH

[TomoHawk]

I'm done with this one.

I got a SPDT rocker switch (center-off, momentary) from my local electronic surplus store, and it fit exactly the square cover that's in the middle on my console (under the radio.) I just cut out the material, a little filing with a square file, and the switch presses in. Then I clipped the pigtail from one of the dead antennas I got from eBay, a little soldering, and it plugs in the hole, the console, and the wiring harness.

After chgarging the battery, I tested the antenna, and it works great- goes all the way up & down. Now I just need a little black vinyl paint for the switch, a couple screws for the antenna bracket, and to put the panels back in the car.

thx