[Boatanchors] SB-303 Calibrator Part Needed

[Walt - WB2VSJ]

Of course NTE had to be different than TI (or vice-versa) and the other DTL
chip makers :) I'll never understand why NTE put Vcc on pin 11 and GND on
pin 4...

The NTE9924 is a quad 2 input NOR gate.  A 74LS02 or 7402 is the same in
function but NOT in pinout.

You can still find the NTE9924 on the web for $11-$15 each. Or you could
make NTE9924 out of a 7402 by moving the pinouts around using an IC socket.
It wouldn't be pretty, but it *may* work. I do don't know about the loading
of a 7402 as compared to the NTE9924.

Got an oscilloscope?  Check the signals going into and out of the NOR gates
on the 25KHz side & also check the voltages on Q602. Q602 is the 25KHz
amplifier (I have a schematic if you need one).

I'm guessing the 100KHz section works just fine?

Good Luck, 

Walt - WB2VSJ


-----Original Message-----
From: boatanchors-bounces at mailman.qth.net
[mailto:boatanchors-bounces at mailman.qth.net] On Behalf Of Mark Johnson
Sent: Monday, February 15, 2010 7:46 PM
To: Boatanchor List
Subject: [Boatanchors] SB-303 Calibrator Part Needed

Team;

I'm in need of IC-601 for the SB-303 Calibrator. This is Heath PN 443-8, or
a Motorola MC724P or NTE9924. 

The 25khz output is not working and I believe that my IC is shorted. Anyone
have one of these? I'll buy an entire BFO/Power Supply board from a scrap
SB-303 if required. 

Thanks!


Mark V Johnson VE3DJU/VE3DDI
______________________________________________________________
Boatanchors mailing list
Home: http://mailman.qth.net/mailman/listinfo/boatanchors
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Boatanchors at mailman.qth.net

List Administrator: Duane Fischer, W8DBF
** For Assistance: dfischer at usol.com ** 


This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html