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[Linrad] Re: Receiving sometimes stop

Hello Leif,

Thanks for your support. I tested the RX10700 again in this
evening. (it is mid-night in JA)

1) Gap is 3cm by my son's old Lego blocks.
2) When had a problem, result of your suggested test was NG.
    When had no problem, it was OK.
3) Local oscillator testing with the spectrum analyzer
      - When had a problem, LO didn't work or maybe worked with
        incorrectly X'tal.
      - When had a problem, voltage of R4, R5, R6 and R10 were
        minus level. And all of X and Y at the U6/U7 were High.
        But it seems to me that hardware test in Linrad was OK.
      - When had a problem, the X'tal selection occasionally
        changed if the coil was touched by my finger.
      - Changing normal/problem by D-sub on/off.
      - working normally at the start but will go problem and
        return to normal suddenly.

I was aware after re-connecting 4 boxed that 143.975,
144.025-075, 125-175, 225-275, 325-375, 425-475 were NG and
others were OK between 143.975 and 144.500 MHz. But all of QRG
are NG now.

I'm very confusing... What is no good in my systems? PC?

tia 73,
Isao / JM1WBB

On 2009/05/26, at 18:06, Leif Asbrink wrote:
> 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

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