AM/FM Antenna Upgrade

Now with the more acceptable exhaust note (the twice pipes were too loud!), I can finally enjoy listening to the radio.  I've struggled with what type of antenna to replace the broken original with.  I first tried an 11" rubber ducky that didn't work very well, as well as a hidden antenna that mounted to the window; again not working too well.  I decided it was time to investigate how to repair or replace the old semi-automatic antenna that Datsun included originally.

The great feature of the Datsun antenna is that it is controlled by the radio head unit with a switch, allowing the driver (or passenger) the ability to raise or lower the antenna to the proper level to tune in stations.  (notice the switch on the upper right)

Unfortunately my car arrived with the antenna broken off.  Modern antennas are fully automatic meaning that they go up when powered up and down when the power turns off.  I needed to find a semi-automatic that I could modify to work with the Datsun radio.  Below is the original antenna (left) and the new one I was able to source (right).  Notice the original Datsun antenna had a modulator box already installed that allowed the switch to power one wire for up, the other for down, and use the body of the antenna for a ground; this is how the switch works too.  The modern semi-automatic that I sourced just reverses the polarity to have it go up and down.

I was able to find a diagram of a door lock actuator that would allow me to use the original Datsun radio switch and wiring while making the new antenna work by means of two relays.  Essentially reversing the polarity of the output wires.  Thanks to the original designer of this diagram, it came in very handy!!  Just need to make sure you get 5-pin (5 pole) Bosch style relays.

Below is my work in progress and then the final cleaned up version.  Two inputs, Two Outputs, and a Ground.

 

Mounting the antenna is fairly straightforward.  After mounting the top to the rear quarter panel I hooked up the wiring to make sure everything worked correct, followed by cleanly attaching the relay bracket that I fabricated and then the antenna mounting bar to ensure my quarter panel didn't move any more than it needed to when the antenna was up.

 

The results are great! I can accurately tune into any station in my '72 240z's radio that I can in a modern car with a digital tuner (meaning the antenna performs as good).

Below are links to the parts I used (not including the extra wire, connectors, and brackets I fabricated):

Semi-Automatic Antenna:
http://smile.amazon.com/MQ-1-Semi-Automatic-Power-Antenna/dp/B004675YOK/ref=sr_1_1?s=automotive&ie=UTF8&qid=1432508441&sr=1-1&keywords=Semi+automatic+antenna

Bosch Relays: 
http://smile.amazon.com/Relay-Harness-Bosch-Style-40AMP-HRNS/dp/B005HFYE1O/ref=sr_1_2?s=automotive&ie=UTF8&qid=1432508382&sr=1-2&keywords=5+Pin+Relay

BRE Rear Spoiler Install

I wanted to change the look of the rear end of the 240z and decided to install a real BRE spoiler from www.BRE2.net.  This is made from the original molds from the 70's and is much better quality than a lot of the replicas that I've seen throughout my travels.  It is a 6-bolt mount (rather than 2 bolt like the cheapo's).

I haven't decided if I'm going to paint it body-color or paint it black...but that will happen once I paint the whole car.

I have never seen any good write ups of how to install one of these spoilers, so I wanted to provide my experience.

First step was to remove the inner hatch panel and remove the "Datsun" and "240z" emblems from the rear deck.  Here's where you can really tell this was a Texas car!  Look at how great the paint looks below the emblems!

 

I then filled in the holes with JB Weld epoxy.  I figure once I repaint the car I will weld the holes shut with real metal, but for now the epoxy would be fine.

Next I decided to make a cardboard template of the spoiler to allow me to identify where the holes should be drilled in the rear deck.  Remember, on this one there are 6 of them that need to be drilled!

 

Then I positioned the template on the rear deck & marked up where the holes needed to be.  I measured many many times to ensure it was correct.  I do know once I finalize the installation, I may need to sand down the fiberglass to get it to line up properly.

 

Then came the most difficult part of center punching the holes & actually drilling out the rear deck.  I did need to make some the holes larger to allow for adjustment.

I did paint the new holes that I drilled to ensure they wouldn't rust.  After a couple test-fittings, I bolted the new BRE spoiler to the rear deck.  There are 2 bolts on either side of the deck (see below) and then two located just above the access holes below.  

 

I've also heard of some guys putting foam on the bottom of the spoiler before it gets bolted on, I may do that to help with the irregularities of the fiberglass and the rear deck.  Overall I'm quite pleased with the outcome.

I did track down the original 70's instructions for how BRE suggests the install...