EMRFD Message Archive 7870

Message Date From Subject
7870 2012-10-15 02:38:19 ha5rxz Missing Value in EMRFD Schematic
First Edition
Page 9.34
Figure 9.62

Just above the LC audio filter U2A there is a resistor in series with the 12V supply, what value should it be? I'm guessing 100 ohms but I would like to make sure.

Peter HA5RXZ
8052 2013-01-06 15:02:33 ep_mand Re: Missing Value in EMRFD Schematic
If you look at the next two schematics, there is the same 100 ohm resistor, but add also 100 microfarad capasitor shown. Also, the OpAmp supplies should have 100nF cap each, always. It's so comm
8066 2013-01-07 12:21:45 Wes Re: Missing Value in EMRFD Schematic
Hello Peter, et al,

The missing values are in the eratta on line, and have been for a while. Just go to http://w7zoi.net/ and then click
8069 2013-01-07 20:26:18 ac2gl Re: Missing Value in EMRFD Schematic
I'd figure something between 47 ohms and 100 ohms should work well. You should also add some power supply bypass capacitors across the power and ground terminals of the ICs so they don't "talk" to each other via the power bus.
Dave - AC2GL