[DSP-10] Voltage readings and more

[kd7ts]

On Sat, 13 Apr 2013 15:32:01 -0700, Don AE5K <donj at ae5k.us> wrote:

> Am I wrong in my assumptions?

Hi Don,

I think this will work to see what is needed.

The 3 part article is online somewhere, but I have local copies in PDF  
format. They expand very nicely on the monitor. I can send as attachment  
in mail or post them and send you a link, if you like.

The second installment has a block diagram that says the 3 transmit stages  
togerther are 40 DB gain. Working from that, backwards says we have about  
-23 dbm from the D1 pin switch. This should be easily seen on the KA7EXM  
meter. I'm guessing it goes to -70 dbm or so.

These are approximates

input -23 dbm 12 -15 mV
mar6  20 dbg
-3
mar4  8 dbg
+5
2n5109 12 dbg
output =  +17 dbm
3 stages together  total 40 dbg

This was all in the article .. just repetitive except the D1:A2 measurement

press the Home key to put the
transceiver into transmit. With the key up,
you should measure the following voltages:

D1-A2	RF Filter TR diode	0.73 V
U4 pin 3	1st transmit amplifier	3.6 V
U5 pin 3	2nd transmit amplifier	4.6 V
Q2 emitterPower-amplifier emitter 1.2 V
Q2 base	Power-amplifier base	1.9 V

Nothing different here than you reported.

The alignment is pretty simple, and is done in receive.

Next, peak crystal-filter coils L12 and L13 for maximum signal. The  
signal-level
indication can be helpful for these adjustments. Select a repeater  
frequency as close as possible to 147 MHz and peak the RF filter coils L1,  
L2, L8, L9, L10 and L11 at that frequency.

I didn't see anything, or recall that there is anything to peak for  
transmit. All these setting do affect transmit, though.

Let me know about the PDF files.

Mike KD7TS