I was thinking about installing a vintage tach in my '30 tudor, I guess one of the old Sun tachs with the "driver" box would be correct, is that so? The car is a late 50's style build. If the Sun tach is the correct time frame, what are the chances of getting one that works? all the ones on e-gay are untested and not much of a way to test one at a swap meet either. Are they dependable? any way to test with a VOM meter?
There have been a few right here on the classifieds lately, some with good boxes. I've found most members here to be very forthright regarding the condition of their items.
They once were long ago, as my friends and I used them. But I bought another (used) one 20 years ago and there were no repro special batteries available then, so I tried to use a "integrated circuit voltage reducer chip" and it did not work for long. When the batteries needed replaced decades ago, there used to be a certain hearing aid battery that would work, but those are long gone now, as those aids had a chest mounted power box for the battery; Back 20 years ago when I bought the used one, I did read that there was at least one shop that would modernize the unit, but I never tried that. Interesting thing that I did learn; is that General Motors used the transmitter box type in heavy duty trucks in/around 1960 + - , with the head mounted in the instrument cluster. However, around 65 or 66 + -, the in-dash unit was now a self contained unit that eliminated the transmitter box. (same exact look on the dash head unit.) .
by the way, boxes had to match your car; 4, 6, 8 cylinders, and there may have been 6v, and possibly positive/neg ground types? I can't remember for sure. I think the 2 batteries were 1.7 volts? at any rate it was not a common 1.5v
Transmitter boxes can be updated to run on 12volts. Tachometer heads are rarely bad, but might need to be calibrated. Your going to spend several hundred dollars for that Sun tach arrangement.
Many times it is but not always. The environment they live in (racing) many times can cause internal tach. problems. The transmitter or "black box" has a battery inside that can go bad. I've seen quite a lot of discussion on the HAMB about this very issue. IIRC, someone has come up with replacement batteries that will work as originals are NLA. Many years ago I bought a new, in the box (NOS) Sun EB9A (V8), transmitter for ten dollars while looking for a tach. at the Portland Swap meet, but never found one reasonably priced so I sold it a year later for one hundred dollars. Now they go for two to three times that. Happy hunting.
F&J I was going to do the IC chip to solve the battery problem also, wonder why yours did not work long? angle drive, I have seen many on e-gay for less than $150 are you saying that is too good to be true? for a working one anyway?
have you found IC to supply the correct volts? Why did mine fail?>I have no idea, and details are somewhat foggy from when I did the IC swap. I maybe? tried 1.5 batteries when I first put the setup into my 66 chevy truck dash, I just can't recall. That was pre-internet. So, I know it had to have been only 10?-15? years ago that with the net, I found 3.4v IC chips on ebay from a seller that handles electronic surplus from factories unsold special use pieces. I was pretty excited to find them, as I think it was 3.4 and I think the stock batteries were 1.7. I believe it worked for a while. I do know at some point soon, the unit went haywire, with needle looking good until it got to 1500-1800, them took off and pinned the needle randomly, then I just unhooked the feed. I'm not up on electronics at all. Mine was a in-dash unit with remote mounted box, all removed from a 60-63 Chevy truck that I got at truck-Carlisle show. I had to buy the whole dash/gauge cluster from the seller, just to get the tach unit and box. It was maybe $180. I should have waited to find the later truck one that needs no box or batteries. Those only differ in appearance by peeking inside the dash unit, which is now "full" with electronics, and my older one has very few things in the head.
I sent my Sun tach, and a empty transmitter box to these guys. They did a perfect job retro fitting to a 12v system. No more batteries.http://www.williamsons.com/Tachometers.php
On my cars I've been buying and using the sixties Sun Super Tach ll's model CP7901 off of ebay including a couple that were NOS. They don't require a transmitter and usually can be had in the $75 range. Getting the transmitter tachs modified is an expensive proposition. Gary
Yes, they have adjustable ones, the circuit has a few more components including a variable resistor but you can get any voltage you need.
oohhhh, you'd better read up on the "adjustable" IC's... I totally forgot that type till you mentioned it. When I was scrounging on ebay for IC's, I ran into those listings and studied up a bit on them. The ones then, were not adjustable with some sort of screw or dial, you had to add a component(s) to one leg to bump the voltage. I think it may need a zener diode. A proper zener-diode raises the volts by one volt when attached inline on the IC leg that goes to ground....from what I recall of a rod magazine tech from late 1970s? They showed how to use the Radio Shack 5v IC, and how to bump it to 6v with a zener, and which zener to buy. I did do one back then on a 6v gas gauge with perfect results, but not a tach. That tech mentioned it was for very low millamp loads. Ok, so 10 years ago for a VW split window bug project, I found a rare 1965 Porsche 365c tach at a junkyard, and it was the first and last year of an "electric" not cable, tach for 356, and it fit the split dash perfectly. (all 356 are 6v) Back on ebay again, I found 6v IC with I think 3 amp capacity so I knew it was more than adequate,. That tach worked flawlessly, so the IC swap must be doable with the Sun, if your Sun components are still OK
Probably the closest to come to an original Sun is this repo unit. No transmitter, 12v. http://www.jegs.com/webapp/wcs/stor...&submodel=&engine=&Nrpp=&No=&persistYmm=false
As Big Duece suggested above: Just bought a Bosch FST8050 from Jegs. Retro tachometer 3 & 3/8". Seems to be a very quality piece and it has the "look" for our 49 Ford. Hope to install it next week. I've been through three of those retro looking units from Moon Eyes (with the little Mooneyes logo on the tach face) and they are Chinese cheap crap - they don't last.
So, if the needle sweep degrees are the same, how about putting the Bosch internals and needle, into the Old Sun case and use the Sun face? If it was cheap junk it would not be work the work, but Bosch sounds promising, and if it works, you are in business for less than sending the Sun out for rehab? .
I would have to dig my ticket out from Williamsons. If I remember right it was 150 or so, plus my cost of tach and empty transmitter box. I did pick up the tach core and box cheap, but probably still spent more than the bosch unit. No regrets on my end. I gave someone some bench work, and kept the $ in the states.
Williamsons does mine. Trying to find batteries that work is fruitless. I like them because they are old school. I paid a lot for the six I have because they look very nice on the outside. The last one I had converted was $150.00
Yep Also, many of the transmitters are pretty eaten up inside from sitting for years with corroding batteries, I've had two like this. There is something about seeing that little black box under the hood of a hot rod though.
F&J that's the kind of thinking I'm into! Also, I saw a picture of the inside of one of the boxes, looks like some type of vibrating points with a coil and some capacitors, those wax type capacitors go bad often and are easy to replace. may be able to repair one?
FYI, Sun Electric became Sunpro who now has become Bosch. I've never been interested in Sunpro or Bosch products as they are not true retro and tach faces state they are Sunpro or Bosch. I find it incredulous of the price they sell the Bosch repop tachs for and some do not even include wiring. Adding $2.00 worth of wiring doesn't seem that much of a stretch to me. Its amazing of how many sixties Sun Super Tach ll's become available on eBay. As we speak there are a couple of NOS tachs for auction right now. Gary
Been looking at similar things myself. I thought this write up was interesting: http://myplace.frontier.com/~wgmumaw/Sun Tach/Sun Tach.html
sold an NOS Sun Super II at the last swap meet.....went cheap....lots of lookers but.....it went to Finland....
sold an NOS Sun Super II at the last swap meet.....went cheap....lots of lookers but.....it went to Finland....
If a push comes to a shove you could get an older style decal made to match OEM instrument cluster like me and use a later tach [emoji106]
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