[DSP-10] Moth balled DSP-10 has some troubles - ADDENDUM

[kd7ts]

On Thu, 11 Apr 2013 17:09:57 -0700, Don AE5K <donj at ae5k.us> wrote:

> Just some additional info addendum to my earlier email today:
>
> I left the DSP-10 running for several hours now, tried checking power  
> output again and it was WAY DOWN, showing 821 uW (microwatts) (-0.8  
> dBm).  This is quite close to what I was getting a couple weeks ago.
>
> All tests have been made in CW mode with power out set at 100.
>
> Later today or tomorrow, will start to check voltages as first step.
>
> Don AE5K

Hi Don,

depending on which instructions you have, TAPR or W7PUA there is a list of  
jumper wires on the back of the board, W-1 through W-29 on pages 2 and 3  
or page 29. These are labeled in the list. This can be useful to identify  
transmit +10. These wires all connect to plated through holes and are  
available on the top of the board.

You can download a copy of the TAPR manual done by Steve Bible here:

http://www.proaxis.com/~boblark/asyman3.pdf

Does the transmit light come on when you toggle the "home" key ? Do you  
hear a sidetone in the speaker or 'phones when you key with the right  
"alternate" key while in transmit ?? If the light does not come on, then  
+10 transmit is missing. If the sidetone is not present, it may indicate a  
problem with the ADSP2181 wiring. (this doesn't seem likely, but is so  
easy to check !!)

Can you listen on another receiver while the DSP-10 is transmitting ? This  
might be useful to see if most of the transmit chain is working. Receive  
and transmit share quite a bit of the circuits, and at the 144 end of  
things are split by D1. +10T is applied to R4>L6 (wire 16) to switch the  
diode and also to L17 (wire 17) to power the transmit rf amp.

Your comment on listening to a marker tells me there is a lot of stuff  
that is correct.

I am unfamiliar with the KA7EXM power meter. Can you verify it reads as  
expected from another source ?

I never got as much power as I hoped, but was eventually able to get +20  
dbm (100 mw).

73 Mike KD7TS