Synchronar resistors

[egomon]

Hi.
I was wondering about the Synchronars resistors and I bought some on my local electronics store. But they are to big ( about 7 cm).The seller pointed out that you can get smaller ones but did not know where.
So my question is: where can i buy about 4 cm long resistors on the net. I was looking but only what I found was the ordinary big ones.
If someone knows anything please let me know.

Regards


Egon

[Old Tom]

The resistors used in Synchronars (and Sinclair Black Watches) are 1/20 watt carbon film types. They have not been made for a long time having been superceded by surface mount resistors- they were pretty much obsolete even when the Synchronar and Sinclair products that used them came out. They do turn up on Ebay from time to time, usually in bandoliers of 100! I seem to remember the Synchronar used very high values and these are particularly hard to come by (1meg up).

[egomon]

Thank you. That's what I was afraid of. Well I will keep my eyes open on ebay or try my luck with surface mount resistors. Anyway thank you for clearing this up for me

[rewolf]

Value is 10-22MegOhm.
I'd use surface-mounted resistors plus wire. If you can't get 10M, then use two or three 4.7M in series.

Ok, just searched in the lab: I can offer you 10M in SMD size 1206 or 4.7M in SMD size 0805. IIRC at home I have a box in the basement with 20-30 years old stuff, inlcluding assorted resistors -will hav a look there as well.

SMD sizes: http://en.wikipedia.org/wiki/Surface-mount_technology#Package_sizes
0805 (2013 metric) : 0.08" × 0.05" (2.0 mm × 1.25 mm)
1206 (3216 metric) : 0.126" × 0.063" (3.2 mm × 1.6 mm)

[Old Tom]

Had a bit of a fish around and it appears Vishay Dale still make 1/20w resistors in 3.8mm by 1.6mm size- CMF50 case. Most of the values are Military specific (which is why they are still being made), but there are a good few Synchronar friendly values available! However finding a stockist might be a little more difficult!