sun super tach sst-709 transmitter

Moderator: Moderators

Post Reply
User avatar
John
Posts: 1904
Joined: Tue Jul 21, 09 10:54 am
Location: Bishops stortford Hertfordshire MMA-369

sun super tach sst-709 transmitter

Post by John »

Bought a nice old Sun Tach at the HRD`S but reading various wireing links and inside the back of the tach itself, it says to use either the EB or WPA transmitters. Needless to say I dont have either so was wondering if there was any way of wiring it without or using some other piece of electronic wonderment.
Lifes Too Fast But The Car`s Not, It even managed to miss the boat twice.
Now passed customs.
Now on route.
Now in posession.
Now costing me sh*t loads.
User avatar
AllKiller
Posts: 15191
Joined: Fri Jun 04, 04 9:33 pm
Location: Hampshire

Post by AllKiller »

Mate thats a Blue question...
he's probably got what you need or can tell you what you need.
I think its a EB-9A transmitter for 8cyl 12v car
:thumbright:

HERE
http://www.ebay.com/itm/Vintage-Sun-Tac ... 0966505544
ALL KILLER NO FILLER
Nostalgia, its not what it used to be.

Carbon footprint of a Saturn V
Image
User avatar
John
Posts: 1904
Joined: Tue Jul 21, 09 10:54 am
Location: Bishops stortford Hertfordshire MMA-369

Post by John »

Yeah thanks mate, already asked blue ...... thought exactly the same as you but even he wasnt sure. wondered if Dave 999 may have known a trick on the wiring side (may have to post it to him for a tinker)

Those bloody boxes add cost to the "what I thought was a good price" peice of kit, plus being old you dont know if their gonna be ok :roll:
Lifes Too Fast But The Car`s Not, It even managed to miss the boat twice.
Now passed customs.
Now on route.
Now in posession.
Now costing me sh*t loads.
User avatar
Dave999
Posts: 9561
Joined: Thu Feb 24, 05 10:31 am
Location: Twickenham,London, England

Post by Dave999 »

http://www.williamsons.com/tachphotos.htm

http://www.leverfamilysite.com/images/P ... ter_EB.pdf



OK sun tach made before 1967 needs a transmitter
after that time the tach was a solid state device and all the gubbins in the transmitter was changed to a transistor and a couple of diodes mounted in the head

the transmitter internals are shown in the picture

as you can see its a simple circuit that causes the relay to close when the coil back emf occurs

when they relay closes the 2.74 volts ffrom the 2 batteries are sent to the tach

i'd guess the tach triggers on a 3 volt square wave.

the batteries are obsolete so you would need to replace and possibly solder in some modern litium iron rechargabel AA batteries that punt out about 1.25-1.4 volts

or build the circuit in picture 2 and use it instead of an orginal transmitter

a company called williamson will convert mk 1 sun tachs to mk 2 spec

nobody knows how they do it but i'm guessing its dead simple but they hide what they have done by filling your tach head with potting mastic

sun tachs had a weight on the pointer it was used to pull the pointer higher than it should be driven by the pulses from the transmitter at RPMs above 3000 this was becasue the transmitter was rubbish at high rpm and short dwell

any converted or DIY triggered tachs need the weight removed...

which is most likely to screw the tach...

akin to doing dentistry on a bee armed only with a hammer


Dave
Attachments
wireing diagram
wireing diagram
sun tach.jpg (39.52 KiB) Viewed 262 times
solid state DIY jobby
solid state DIY jobby
sun tach DIY transmitter.jpg (22.82 KiB) Viewed 262 times
the original transmitter
the original transmitter
suntach transmitter EB.JPG (51.62 KiB) Viewed 262 times
The Greater Knapweed near the Mugwort by the Buckthorn tree is dying
User avatar
AllKiller
Posts: 15191
Joined: Fri Jun 04, 04 9:33 pm
Location: Hampshire

Post by AllKiller »

Dave , John would have to spend money....he dont like doing that :lol:

Could buy a converted one and melt the mastic out to see what they have done :thumbright:

Lots of potential to cash in for a little outlay
ALL KILLER NO FILLER
Nostalgia, its not what it used to be.

Carbon footprint of a Saturn V
Image
User avatar
John
Posts: 1904
Joined: Tue Jul 21, 09 10:54 am
Location: Bishops stortford Hertfordshire MMA-369

Post by John »

Wow now Im stumped........ :?
Lifes Too Fast But The Car`s Not, It even managed to miss the boat twice.
Now passed customs.
Now on route.
Now in posession.
Now costing me sh*t loads.
User avatar
Dave999
Posts: 9561
Joined: Thu Feb 24, 05 10:31 am
Location: Twickenham,London, England

Post by Dave999 »

use a pair of watch batteries or AA batteries stacked to make 3 volt cell

connect the bottom to the meter negative

and ping the positive wire from the battery off the + by jiggling alot across it with the bare end...you need to do 2 -4 jiggles a second to maintain a 200 rpm

if the neddle jumps in a small and flaccid way your tack works and it is worth while investing in

DO NOT CONNECT THE + and leave it

PS sent you a quick note on how to make a circuit on bread board or tag strip, easier on tag strip if you can't solder neatly.

bit more in keeping with age of car as well :)

Dave
The Greater Knapweed near the Mugwort by the Buckthorn tree is dying
User avatar
John
Posts: 1904
Joined: Tue Jul 21, 09 10:54 am
Location: Bishops stortford Hertfordshire MMA-369

Post by John »

Dave999 wrote:use a pair of watch batteries or AA batteries stacked to make 3 volt cell

connect the bottom to the meter negative

and ping the positive wire from the battery off the + by jiggling alot across it with the bare end...you need to do 2 -4 jiggles a second to maintain a 200 rpm

if the neddle jumps in a small and flaccid way your tack works and it is worth while investing in

DO NOT CONNECT THE + and leave it

PS sent you a quick note on how to make a circuit on bread board or tag strip, easier on tag strip if you can't solder neatly.

bit more in keeping with age of car as well :)

Dave
Love your "quick note" Dave your a star but far too complcated for the likes of me lol
Lifes Too Fast But The Car`s Not, It even managed to miss the boat twice.
Now passed customs.
Now on route.
Now in posession.
Now costing me sh*t loads.
User avatar
Dave999
Posts: 9561
Joined: Thu Feb 24, 05 10:31 am
Location: Twickenham,London, England

Post by Dave999 »

just like airfix mate

download a list of circuit symbols and a resistor bands chart

can't go wrong

anyway PMed ya

work out if the tach works ....

Dave
The Greater Knapweed near the Mugwort by the Buckthorn tree is dying
Post Reply