[Linrad] Re: Receiving sometimes stop

[Leif Asbrink <sm5bsz.com; leif@xxxxxxxxxxxxxxxx>]

Hello Isao,
 
> It seems that my RX10700 has problem. While trouble condition,
> Linrad get a signal on 2.5 MHz and doesn't get a signal on
> 10.7 MHz from signal generator. (HF Rig with dummy load)
You might try to put the 9-pin dsub that belongs to the RX144
into the RX10700 to see if you have the same problem.
(Both units have 4 crystals.)  Select 144.0, 144.5, 145.0 or
145.5 and test with the signal generator for signals at the
RX144 input which should be centered at 10.675, 10.7, 10.725
or 10.75. (Ignore the error messages for non-connected units)

In case there is a poor connection in the dsub(s) chances are good
you will detect it this way.

If the RX10700 does not show anything even with a very strong
input signal, the LO is most probably not running. Did you
try to change the frequency in the 10.7 band to see if another
frequency works.


> And I saw two other statuses of the waterfall. One was 3 times
> only:
> 	http://gongon.com/JM1WBB/linrad-2.png
> Two is continuing:
> 	http://gongon.com/JM1WBB/linrad-3.png
> last one is like self oscillation or using super preamp and I
> get big noise from PC's speaker.
When a WSE unit is powered up and before Linrad has sent a 
command to it, the state of the latches holding the info about 
which crystal to use is undefined. It could be no crystal at all
or it could be several crystals. When several crystals are
selected, several oscillator transistors are powered simultaneously
and the total gain in the LO becomes too high causing various
peculiar phenomena.

Every time a unit has been without power it has to be programmed
by Linrad to start working again. If you are in a receive screen,
type 'X', then 'B'. It is not enough to just select a frequency.
Linrad would only send data to the units that need re-programming
and trusts that other units still remember their settings.

> It will go to normal level if
> outputs from RX10700 is offline. 
Yes, the RX2500 only has one crystal so it does not have any
memory.

> I was aware that WSE boxes are
> heating. Then, WSEs are cooled by electric fan and was reseted
> by power OFF/ON, WSEs is working well now. But I got cold :)
> 	http://gongon.com/JM1WBB/linrad-4.png
> 
> Must WSE boxes have forced air cooling? 
No, but they must not be allowed to heat each other. 
Normal temperature is 45 to 50 degrees with boxes vertically
and a 3cm air gap between boxes with provision for air to get 
in from beneth and out at the top.

> I suspect the gap is
> needed more and someone said it is needed 2cm gap at least
> before... Gap of current setup at test bench is about 1 cm.
Check the temperature. The units should work properly at much
higher temperature, but the lifetime of electrolytic capacitors
would suffer. 

In case the RX10700 oscillator stops working at some specific 
temperature I think you would find that the other three
crystals still work at that temperature. If they do not there could
be some other temperature related error. One of the serier regulators
might turn off for example.

73

Leif / SM5BSZ

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups "Linrad" group.
To post to this group, send email to linrad@xxxxxxxxxxxxxxxx
To unsubscribe from this group, send email to linrad+unsubscribe@xxxxxxxxxxxxxxxx
For more options, visit this group at http://groups.google.com/group/linrad?hl=en
-~----------~----~----~----~------~----~------~--~---


LINRADDARNIL