The optional Power Antenna was mounted on the left hand rear quarter of coupe and sedan models. The aerial was a high quality unit made by Harada in Japan and usually gave a very long service life.
It was operated by a rocker switch on the dash that enabled raising or lowering of the antenna. If the antenna was not manually retracted before turning the car off, the antenna mast stayed in its most recent position.
Unfortunately, some unlucky owners returned their car to find their expensive power aerial snapped off by vandals. From HX models onwards, a relay was added to automatically retract the aerial when the ignition was turned off.
The other failure mode of the aerial occurred when the nylon “rope” inside the mast, that drove the mast up and down, would break. After 20 or 30 years of service, the nylon “rope” would become brittle. The constant winding of the rope onto a circular spool inside the motor housing and then unwinding to be straight when the mast went up, would cause the nylon to fracture.
Replacement masts and “rope” were available from Holden spare parts for until about 1990.
Fitting an aftermarket replacement mast:
The nearest equivalent replacement mast I have found is an Aerpro AP …. as used on Mitsubishi ………………….The largest section of the 5 section mast is the same diameter as the original Holden unit. Unfortunately, the replacement units have 3 key differences. When completely retracted, it is approximately 25mm shorter that the factory original. This means that when fully retracted the tip of the antenna will go about 25mm below the top nut off the antenna assembly. This can be compensated for by tapping the “Up” rocker switch until the tip is nicely positioned at the top nut.
Another issue is that the tip of the Aerpro mast is not the same shape as the “bullet” tip of the original. However, the tip will unscrew and if you have an original mast, you can screw the original bullet tip to the replacement mast.
The final issue, and the most significant is that the nylon “rope” is a larger diameter (xxmm) and is “toothed” The original Holden “rope” is XXXmm in diameter and smooth, ie not toothed. This means that the retracting wheel and “rope” winding spool are strained in managing the larger diameter “rope”. It can be made to work though.
After many years of use, the internals of the motor housing can become clogged with dust and dirt mixed with lubrication grease. Additionally, water gets in through the aerial mast, flows through the mechanism and out the drain hole through the drain tube to the outside. Before going down the path of buying a replacement mast, it is essential to dissemble the unit’s drive system, clean it out and re-lube it AND then check that raising and retracting system works freely. If it is not recoverable, don’t waste money on a mast.
After my mast’s “rope” finally snapped on a freezing cold morning after 48 years, I experimented with the replacement mast as above. However, I did not like it retracting below the top nut so decided to go for an aftermarket unit
Using a new, aftermarket aerial assembly:
I chose an Aerpro model AP22 Multifit Auto Antenna costing approx $70.
All modern auto aerials are wired differently to the original HQ aerials. They expect a permanent 12 volt feed to one wire (red wire) that drives the aerial down when the ignition is turned off. To drive the aerial mast up, the 2nd wire to the aerial (green wire) has to receive 12 volts also.
This is incompatible with the HQ Up / Down rocker switch and the feed wire pair to the aerial. I have developed a simple and cheap adapter unit using 2 relays, that convert the aftermarket aerial so that it behaves identically to the original HQ aerial. The parts cost about $15 and are all available from Jaycar. All you need is a soldering iron and some insulated wire to make it.
Here is the adapter circuit and parts list.