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

[Joe]

Don,

I think that the jumper between the two RCA connectors is the transmit 
RF before the PIN diodes.  This is where I place an attenuator when I 
need only a Milli-watt of excitation.  Maybe you could measure the power 
there.  Or is the jumper missing?

Joe WB8DNO

On 4/12/2013 12:35 PM, Don AE5K wrote:
> 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
>
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