Put the $24 Tach through its paces today

[scottr]

Ground

Mine turned out dead on accurate. My 7900 hits the rev limiter at 13,500. At that point it would retard to 12,600 cutting out.
I then reset it to 13,330 for now. Dead on hitting limiter.

I did learn one thing on it. It is groundless ok, but there is a ground area pin on the back, on the top right of the hook up. If you put your finger on the ground pin it seems to read quicker.
But hey what do you want from a $24 throw away tach, i feel I already got my monies worth taching about 9 saws that I had tuned by ear.

Kevin , is there anything in the instructions about adding a ground wire for a reference ? The fact that your finger on the ground pin changes the responce time makes me think that it needs grounding .

 

[Cut4fun]

Kevin , is there anything in the instructions about adding a ground wire for a reference ? The fact that your finger on the ground pin changes the responce time makes me think that it needs grounding .

No instructions for $24, They wanted a extra $5 for those.:hmm3grin2orange:

Just jking scott, but did go to another makers tach site and they suggest wrapping the wire 4 times, I have only been doing it once. Heres a pic of the other makers way of wrapping.

 

[scottr]

Kevin , maybe more turns around the spark plug wire will help but if you give them a call or email they can answer that question and the ground question . I've used a lot of counters and they were all grounded .

 

[ShoerFast]

The tach would be using the field around the plug-wire, that field would be just a stray currant intell grounded, my bet is that it would be faster. Just from the hip. but toying with it would show what works best.

 

[CUCV]

I just got my tach's in and was disapointed that no instructions were include. Here are the tech specs from the web site which give a bit more info http://www.enmco.com/pdf/678.PDF
I really wanted the surface mount or the bolt on version but they were backordered... so I got the panel mount. The sample rate is "approx. 1 sec" which is half the rate of other tachs I have looked at. From the tech spec they show the tach being grounded, too bad they couldn't have put an electrical fitting on the ground like they do for the wire that goes around the spark plug.

 

[Cut4fun]

From the tech spec they show the tach being grounded, too bad they couldn't have put an electrical fitting on the ground like they do for the wire that goes around the spark plug.

This could explain the slow reads maybe. Hmmm, how to ground the little solder bump, grrrrr. Looking at the back top right is the ground, Found by trial and error of finger.

 

[Lakeside53]

You are a perfectly good ground for the RF (very high frequencies from the rapid rise of the ignition voltage/current spike) that's being measured. Just put your finger on it. There is no need to physicilly wire that anywhere, and in fact, a wire might be a worse ground than you ("skin effect" in small conducting bodies). I'll let you Wikipedia that..

 

[Cut4fun]

I did notice a difference in it a few days ago with grounding with my finger.
But still to slow for my likings when on the modded saws(rev quick), ok for the stock ones.

 

[scottr]

Gator clip

Kevin a gator clip would probably grab the edge of the terminal well enough to compare the reading to the reading that you get with your finger on the terminal .

 

[Elmore]

I just got mine this evening and the ones I got have two male pins. The pin on the left is labeled "P" and the pin on the right is labeled "N". "N" for neutral or for ground.

 

[04ultra]

I just got mine this evening and the ones I got have two male pins. The pin on the left is labeled "P" and the pin on the right is labeled "N". "N" for neutral or for ground.

Should have said something elmore I could have saved you some money..


.

 

[Elmore]

Should have said something elmore I could have saved you some money...

How?...you giving them out as Christmas presents?

 

[04ultra]

How?...you giving them out as Christmas presents?

How many did you buy??

.

 

[Elmore]

How?...you giving them out as Christmas presents?

I've been real good lately...honest...send me one of those nifty, wireless STIHL tachs...Santa please!

 

[Elmore]

How many did you buy??

.

The minimum required for the discount.

 

[04ultra]

The minimum required for the discount.

Ok ....I have 1 extra...

.

 

[Cut4fun]

Is the stihl wireless tach the model 5.
Wanting a top of the line tach for the modded saws, they rev so darn fast. Stock ones are fine for the cheapie one.

 

[Lakeside53]

all Stihl's tachs are wireless. The 5 has just been replaced by the 8.

 

[Cut4fun]

Lake the dealer told me he could order a model 5, 7, 8, 302. I just posted this in the thall thread too.

 

[Freakingstang]

I have the 302 and it works great. It is the same one Eric has. Will work wireless or you can put the wire on it if you want. Cost 99.99 for the dealer about 8 months ago. Nice little size with a big readout display. I think they discontinued it though....