[DSP-10] DSP-10 troubleshooting - false alarm

[Don AE5K]

Thanks Mike...

Part of my handicap on this is unfamiliarity with some of the operation 
of the DSP-10. I found this morning, after turning things on, that I had 
been misreading the command list and using Scroll S on the sidetone 
volume.  Of course, this should have been Scroll D to increase the 
volume, and when I did, I did receive a nice sidetone using the straight 
key or the right ALT key.  So that was a false alarm, sorry about that.  
(BTW, I would have thought the S stood for sidetone (up) and D for 
sidetone "down" in volume; I just didn't read the cheat sheet summary 
properly)  I now see what the numbers mean on the screen after "Mode" 
and also the display at lower left showing either STONE- or STONE+ now 
becomes meaningful.

Just as a side note, I had to do power down reboot/reload five times 
this morning from a cold start environment (roughly 60 degrees F).  One 
was where I got a bunch of ASCII-hex data bytes displayed on the screen 
during the Ezload.  Three times it just hung after the UHFA 1 command.  
Each time I powered down both DSP-10 and laptop between tries. Finally 
success on the 5th time. Something is not right on this, but not a 
killer problem at this time.  Once in operation, got the usual 2.31 mw 
output +3.6 dBm on the meter.

I sent the transmit portion of the schematic to a ham friend for 
comments and he suggested I look at the PIN diode switch D1 at the start 
of the tx amp chain.  I'll do that shortly and also start with voltage 
measurements.  I'll post them and anything else I find out, either 
normal or abnormal, when completed.  His reasoning was, with the gain of 
U4, U5, and Q2 (30-40 dB ?), what I'm seeing at the output may be just 
leak thru of the PIN diode if it is not conducting.  I'll check it.

Don AE5K


On 04/11/2013 10:45 PM, kd7ts wrote:
> On Thu, 11 Apr 2013 20:17:41 -0700, Don AE5K <donj at ae5k.us> wrote:
>
>>
>> Sidetone - ***NO!*** - no sidetone heard.  I tried "Scroll S" and it 
>> does nothing that I can see, HOWEVER, I now get in lower left corner 
>> the error message when doing the Scr S:
>>    "E1 DSP Data Lst"
>> followed by the line "STONE-"
>
> Hi Don,
>
> On the main board near the front corner of the 2181 enclosure is an 8 
> pin connector P5 that mates with J5. the wires go to the feed throughs 
> on the 2181 enclosure. PIN 4 and PIN 6 are the audio for transmit and 
> sidetone. PIN 6 is the sidetone audio and PIN 4 is the transmit audio.
>
> IF you have made an SSB contact it seems these must be correct, or at 
> least the wire on PIN 4 must be correct. It is possible that the audio 
> connector out of the DSP-10 enclosure is causing the symptom. Take a 
> close look at the connector and be sure it goes in far enough to seat 
> all the way. The enclosure is pretty thick metal, and it is possible 
> the connector is not mating completely. This is evident on receive as 
> having audio on left or right, but not both.
>
> Sidetone only appears on one channel, receive audio, on both.
>
> 73 Mike KD7TS