Folks:
A couple builders have had trouble getting their Tuning Indicators to
function properly.
I hope the following readings (taken from my working unit) will assist you
in locating the problem
NOTE - USE EXTREME CARE when probing the pins of the 2211 IC to avoid
shorting adjacent pins together. Bad thing can happen.
If anyone else gets significantly differing readings, I'd greatly
appreciate knowing of it... may need to 'modify' my observations a bit.
73,
Tom N0SS
-------------
K6XX CW Tuning Indicator - SMD Version
Representative Resistance & Voltage Readings
Test Conditions:
CW Tuning Indicator UNplugged from K2
Measurement device: Fluke 187 DMM
DMM Negative Lead connected to PC board header Pin 3 (GND)
2211 Approx.
Pin Resistance
1 6 M
2 11 M
3 400 k
4 0
5 >6 M
6 >10 M
7 >10 M
8 6 M
9 >10 M
10 4 M
11 850 k
12 38 k
13 >10 k
14 9 M
-----------
DC Voltage Readings
Test Conditions:
CW Tuning Indicator connected to K2
K2 turned ON
Band: 75M (4.000 MHz birdie)
AGC: ON / FAST
PRE: OFF
Measurement device: Fluke 187 DMM
DMM Negative Lead connected to PC board header Pin 3 (GND)
2211 NO-LOCK IN-LOCK
Pin DC Volts DC Volts
1 5.0 5.0
2 2.5 2.5
3 0.2 4.8
4 0 0
5 1.6 0
6 <0.03 0.1
7 0.1 0.1
8 5.0 5.0
9 <0.01 0.04
10 1.7 1.7
11 1.0 0.1
12 1.7 1.7
13 2.8 2.8
14 2.8 2.8
-----------
AC Voltage Readings
Test Conditions:
CW Tuning Indicator connected to K2
K2 turned ON
Band: 75M (4.000 MHz birdie)
AGC: ON / FAST
PRE: OFF
Measurement device: Tektronix 2236 X1 probe
Negative Lead connected to PC board header Pin 3 (GND)
2211 NO-LOCK IN-LOCK
Pin AC Volts AC Volts
1 0 0
2 50-100 mV 50-100 mV (AF Input from 4 MHZ birdie)
3 Random 0
around 2V
4 0 0
5 0 0
6 0 0
7 0 0
8 0 0
9 0 0
10 0 0
11 Random 1.0-3.0
around 4V
12 0 0
13 1.0 1.0
14 1.0 1.0
-----------
73,
Tom N0SS
_______________________________________________
Elecraft mailing list
Post to: [email protected]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com
