How old is this sun tach & other questions

Good idea on the re chargeable. I've got a buddy who has a 68 Impala that still has a points type distributor, on Sunday we're going to pop a couple of rechargeable batteries in the transmitter and see if this baby still works.

 

If you purchased the tach and box for $90, you didn't get burned at all. Both appear to be in great shape. To find a date for the tach, take the cup off and look at the back of the tach head. There's likely to be a three or four digit number hand stamped in red or white ink, such as "516" or "1168." The number on the right end in the first example equates to 1966. The last two digits in the second example equate to 1968. A quick way to get a close approximation of the date is to look at the tag on the back of the tach head and see how Sun's address is written - this goes for the tag on the transmitter, too. The Post Office implemented the "zip code" on 1 Jul 1963. It wasn't mandatory and it took a couple years for everyone to start using it. So, if the address is the old style, "Chicago 31, Illinois," it is pre-Jul 63. I believe from the pix that your transmitter has the old style address. You'll note on the face of the tach, at the bottom, in small letters it says "Mod SST-70." Mod is Model, SST is Sun Super Tach, and 70 is a 7k RPM range. I believe Tommy is correct that this model was introduced in 1963. I don't recall a version with a plain black face and I believe he is thinking of the Dixco Tachs. In the ad, which is black & white, it sez the tach dial used color. The green was first. I believe it was 1965 or 1966 that the blue line version came out. They spelled out "SunSUPERtach" on the face, but if you look below it you'll see something like Mod SST-709 or Mod SST-802. They changed the way they used the numbers, but it was still a Sun Super Tach (SST). I believe all the green line tachs used a transmitter (mite be wrong here as the memory fades) but the blue line models cud be had in either a transmitter or electronic version. An even numbered right-hand digit was the electronic version. They used different numbers for the various rpm ranges. They were in production until the '70s when the Sun Super Tach II came out. If you're going to put a tach into a '53 Chevy and really be period correct, you'll want to use a "RC" model Sun tach, which has the red "football" on the tach face. But, in my opinion, you'd still be correct using your SST-70 as it falls into a 10 year range and looks good. But, you have some decisions to make as to what facet is more important to you. One of the Dixco tachs wud look good in there, too. They're currently not in demand as much as the Sun and are all electronic with a period correct look because they are from that period. Someone from L.A. sold one on Ebay a couple months ago for about $20. They have several diodes on the back to make them compatible with 4, 6, or 8cyl. You just clip off the ones you don't need. So, if you go this route, make sure it has all the diodes you need on it to fit your situation. I think you probably can use the AA batteries in the Sun transmitter without too much deviation, but you'll be changing those batteries quite often. I'd do some research and get a lot of feedback from those who have chosen that route. Hope I've helped you some. Let us know what you ultimately decide. Good Luck!

Tommy - if you're still listening in, I'll see ya Friday nite at Keith's.

 

On the face of the tach underneath the R.P.M. Hundreds it reads Mod.SST-70
SUN ELECTRIC CORP. CHICAGO, ILL. U.S.A. 897-010

Here's a pic of the back of the tach

 

This is why I said earlier that the correct batteries and clock cycle are important for perfect accuracy. Being 1,000 RPM off should be easy to hear, but I'd sure not want to chance it with my engine.

I'm also fairly certain that these transmitters only work with points ignition.

 

I think I'm going to test this one out on my friend's Impala on Sunday and if it works, sell it and look for a Dixco

 

That's Chicago 31, IL as an address and a 543 stamp on the back of the tach head. I'd say your SST-70 is a 1963 tach. Since I was writing what seems to be a novel, I forgot to mention that the same type of stamp might be on the bottom of the transmitter box. It usually gets worn off or mostly because it's in the elements, but yours looks pretty clean, so the stamp or remnants of it may still be visible. If you can see it, you might have a more specific date stamped on it. In any case, with the address on the tag on the box top, it's likely from before Jul 1963. I'd say you have a really nice set and for $90, yet. Many times it is a mismatched set that is being sold, i.e., a "football" tach, which is definitely '50s, and a transmitter box that has the current five-digit zip code on the tag, which is Jul 63 and newer. In a phrase... ya done good!

 

That tach looks like brand new inside and has the original light socket and lead. I'd think you cud easily get more for it than what you paid. I'm sure whatever you decide to do will be the best decision. You're the only one you need to satisfy.

 

As promised, obviously quite different, yet very similar.

 

Here's a couple Dixco's and their backside so you can see what I was talking about.

 

The more I think about it I think the Dixco is a no-brainer for what I need. It works with the electronic ignition, made in the USA, has the look and less demand means lower price.

 

90 bucks is a steal as far as I'm concerned. I picked up a green line tach at a swap meet a while back for $50. Had a good meter so I went searching for a transmitter. Had to pay $175.00 but it was a new old stock one in its original box. I had a HEI on the nailhead to start with but the tach was eratic. Changed back to points and it straightened out. I'm using duracel 1.5 volt batteries and according to my Snapon digital timing light/tach it is reading about 10% high. I can live with that. Dont want to over rev the hailhead anyway. Looks right at home in the company hauler.

 

Modern NiMh AA batteries are 1.2V How much lower than 1.35 can it go?

Unless there is some strange isolation needed, I'd just go with a little regulator circuit to make 1.35V.

 

That looks good, the box looks right at home on the firewall and so does the tach on the column. I really like the look of the older Suns.

 

The Sun transmitter circuit looks to me to be some what dependent on constant dwell and seeing how the HEI varies the dwell I think it may not work all that well with the HEI. I converted my Sun transmitter to electronic and its written up on my web page along with accuracy results.

 

Bill, thanks for sharing. Did you ever get it hooked up to the car, and if so, how did it work?

 

It was working fine in the car but while trouble shooting another circuit mounted next to it, I managed to short something out and killed it. Haven't had a chance to see what happened yet; I'll update my web site as soon as I get it going again.

 

I also had Williamsons convert my Sun Tach, it wasnt cheap but it works great and looks completely untouched on the outside.

 

These old Sun Super Tachs have been discussed to death over the years. It's been my experience that the difference between the Green Linne and Blue Line is; the Green Line units required the sending unit (such as the EB-9A) and the Blue Line units were 'transistorized', ... or self-contained. Another obvious visual difference is, the Green Lines were available as 7K & 9K while the Blue Line were 8K & 10K, but I see Muttley blew that theory out of the water. ;-)
Also, if I recall a previous thread, the original batteries were Mercury type at 1.35 volt. (Good luck finding MERCURY batteries!) You CAN substitute other battery types, but their performance is poor at best. The Mercury batterys worked at 1.35 volts throughout their life. They either worked, ..... or they didn't! They didn't fade away, they just died. The replacements start out at 1.5 volts and continually degrade. So, in theory, they will work well for the short time they are supplying an exact 1.35 volts, .....

And as others have mentioned, these senders like the old point type distributors. Nothing else.

 

Sorry to shoot so many holes in your theroy but my Blue Line requires a box also.

 

No need to apologize.. Life's all about experiences.

 

Well I found the problem; the head of the screw for the negative terminal on the back of the meter had broken off and there was no connection to the negative side of the meter internally. So the circuit should be fine.

 

Dig the vintage "roll control"

 

Then you might enjoy reading this.

 

Yep, I did enjoy that story. I remember when most of the tuff stick shift racers had em'. Didn't the Pro/Stock boys run them too?

 

You got me..................they were obsolete before I was born.

 

Well, we tried it out in my buddy's Impala and didn't have any luck, so he took it to his brother who's an electrician. He worked his magic and viola, a working tach. I'm pretty happy about that.

 

Foot Ball 1962

 

Awesome. Did you use rechargeable batteries, as mentioned earlier, to power it? How accurate is it? (If you know)

 

Think I have a dixco like this kicking around in a big box full of gauges I bought cheap at a swap meet about 20 yrs ago. I should check. I snagged it at the time because there were a couple SW green stripes and a SW cable tach in there as well. Think I paid $30 for the whole shittery.

 

Question. Is there any relation between the color of the label on the sender (red or orange) and its age?