[sdiy] Electro Notes, #87, pg 18 March 1978

[David Ingebretsen]

In my quest for a delay using the MN3005, I found this gem in Electro Notes,
#87, pg 18, March 1978.

I have a question on the schematic, please. There is an exponential VCO
using a 2N3904, and 2N3906. The tempco is from the base of the 2N3904 to
ground. There is a 470K from the base to the positive supply. Now, I have
some 2K and 1K tempcos.

So, this looks like a simple voltage divider so can I use a 523K and a 2K
tempco, or a 261K and a 1K tempco instead? Am I missing something else?
There is a 0.01 mFD cap from the base to ground as well. Does this screw me
up?

(Is Jan Hall, the author of the schematic on this list?)

Thanks
David 

David M. Ingebretsen M.S., M.E.
Collision Forensics & Engineering, Inc.
2469 East Fort Union Blvd. STE 114
Salt Lake City, UT 84121
www.CFandE.com

801 733-5458 Office
801 842-5451 Cell

dingebre at CFandE.com
dingebre at 3dphysics.net