62 Factory Tachometer Transmitter Box - The 1947 - Present Chevrolet & GMC Truck Message Board Network

62ShortStep · 11-11-2010, 11:49 PM

I have a factory tach to install in my 62, but I'm beginning to realize these tachs were used with a transmitter box.

What does the box do? Is it used to adapt 6 vs 8 cylinder engines to the same tachometer type?

Is anyone making it in reproduction, or selling good original units? I see some on eBay, but I'm not sure what to watch for.

markeb01 · 11-12-2010, 01:09 AM

On the early “two piece” Sun tachometers, the tach head was merely the gauge, and the transmitter box was essentially the sending unit that told the gauge what rpm to display. Each tach head normally has information on the back stating what type of transmitter is needed for that series head. Selecting a transmitter is a matter of picking the correct voltage, number of cylinders, and positive or negative ground. Note there are also transmitters for magnetos which will not work on conventional ignitions.

These early transmitters may or may not work on anything but old points style distributors. Additionally, they used a unique 1.35 volt battery which is no longer produced. Fortunately there are a couple of outfits that can retrofit these tachs with new electronics, eliminating the battery:

http://www.streetrodderweb.com/tech/...ter/index.html
http://www.williamsons.com/

http://www.autoinstruments.com/

Also here’s an earlier thread that may provide some additional helpful information:

http://67-72chevytrucks.com/vboard/s...light=sun+tach

62ShortStep · 11-12-2010, 03:10 AM

Thanks Markeb01. Thats a lot of information and I'll start digesting it as soon as possible.

The oem tachs look like they work on the same principle as the Sun tachs. I see the Sun tachs/transmitters on eBay, but I see no oem transmitters.

Two questions that immediately pop into mind are:
1) Can a Sun transmitter be used with an oem tach?
2) Can the oem tachs be converted to solid state?

raycow · 11-12-2010, 09:02 AM

OEM tachs that used a transmitter were made by Sun and are electrically the same as aftermarket units. If you can find a Sun aftermarket transmitter, it will work with the OEM tach. There are instrument repair outfits that convert the transmitters to solid state which eliminates the need for batteries.

Ray

62ShortStep · 11-12-2010, 09:16 AM

Thanks Ray...thats great to know.

11-11-2010, 11:49 PM	#1
62ShortStep Registered User Join Date: Sep 2010 Location: Fountain Valley, CA Posts: 179	62 Factory Tachometer Transmitter Box I have a factory tach to install in my 62, but I'm beginning to realize these tachs were used with a transmitter box. What does the box do? Is it used to adapt 6 vs 8 cylinder engines to the same tachometer type? Is anyone making it in reproduction, or selling good original units? I see some on eBay, but I'm not sure what to watch for.

11-12-2010, 01:09 AM	#2
markeb01 Senior Enthusiast Join Date: Feb 2007 Location: Spokane Valley, WA Posts: 8,356	Re: 62 Factory Tachometer Transmitter Box On the early “two piece” Sun tachometers, the tach head was merely the gauge, and the transmitter box was essentially the sending unit that told the gauge what rpm to display. Each tach head normally has information on the back stating what type of transmitter is needed for that series head. Selecting a transmitter is a matter of picking the correct voltage, number of cylinders, and positive or negative ground. Note there are also transmitters for magnetos which will not work on conventional ignitions. These early transmitters may or may not work on anything but old points style distributors. Additionally, they used a unique 1.35 volt battery which is no longer produced. Fortunately there are a couple of outfits that can retrofit these tachs with new electronics, eliminating the battery: http://www.streetrodderweb.com/tech/...ter/index.html http://www.williamsons.com/ http://www.autoinstruments.com/ Also here’s an earlier thread that may provide some additional helpful information: http://67-72chevytrucks.com/vboard/s...light=sun+tach

11-12-2010, 03:10 AM	#3
62ShortStep Registered User Join Date: Sep 2010 Location: Fountain Valley, CA Posts: 179	Re: 62 Factory Tachometer Transmitter Box Thanks Markeb01. Thats a lot of information and I'll start digesting it as soon as possible. The oem tachs look like they work on the same principle as the Sun tachs. I see the Sun tachs/transmitters on eBay, but I see no oem transmitters. Two questions that immediately pop into mind are: 1) Can a Sun transmitter be used with an oem tach? 2) Can the oem tachs be converted to solid state?

11-12-2010, 09:02 AM	#4
raycow Registered User Join Date: Mar 2003 Location: San Francisco, CA USA Posts: 2,454	Re: 62 Factory Tachometer Transmitter Box OEM tachs that used a transmitter were made by Sun and are electrically the same as aftermarket units. If you can find a Sun aftermarket transmitter, it will work with the OEM tach. There are instrument repair outfits that convert the transmitters to solid state which eliminates the need for batteries. Ray __________________ Live more responsibly. Eat lower on the food chain. Eat vegetarians.

11-12-2010, 09:16 AM	#5
62ShortStep Registered User Join Date: Sep 2010 Location: Fountain Valley, CA Posts: 179	Re: 62 Factory Tachometer Transmitter Box Thanks Ray...thats great to know.



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