[UK-CONTEST] FT1kMP CAT problem

[Chris G3SJJ]

  OK, thanks Bob, and also Neil G3RIR and Phil GJ4CBQ for their detailed instructions. I think you are correct Bob the board would be better taken 
out, it's not a great task, the 20 connectors are well planned, (not like the TS930 that I used to work on!) I also think removal of the 2 closest 
electrolytics would be helpful. I think I will get someone to do the swop. My eyesight still hasn't fully recovered from the recent detached retina 
surgery, at least not enough to do this kind of work. Pity you aren't still in the UK, we had lunch in Malton last week!

Phil also suggested that common mode currents flowing in the CAT lead when the 2nd tx was txing might be the reason for failure. That sounds like a 
good possibility.

73 Chris G3SJJ



On 25/08/2010 06:41, Bob Henderson wrote:
> Hi Chris
>
> The MAX232CWE is a wide 16 pin SOIC.  There are narrow MAX232 chips with
> equivalent functionality but which won't fit the tracking.  For some reason
> my search of Farnell UK only comes up with the £3.35 version.  I can confirm
> this device to be suitable.
>
> I do suggest you find someone experienced at SMT replacement to do this for
> you.  Without complete removal of the PCB, access for removal of the dead
> MAX232 is awkward.  Also, the tracking around this chip is very narrow and
> easily lifted from the PCB substrate.  I cannot recommend this as a first
> step SMT learning experience.  I would happily replace it for you but
> bringing it round would be a bit of a trek.
>
> Good luck in finding an SMT man.
>
> 73 Bob, 5B4AGN
>
> On 24 August 2010 20:18, Chris G3SJJ<g3sjj at btinternet.com>  wrote:
>
>>   An update on this as several people are interested and others may yet
>> experience it. Thanks to a hint from G4EOF and a (yet another!) long Skype
>> chat with Paul, ex G4BKI, now W4/VP9KF, also some fairly recent postings on
>> the Elecraft Reflector.
>>
>> The FT1kMP CAT interface is a standard TTL to RS232 chip and can be
>> susceptible to surges. There was a thread on the Elecraft Reflector and
>> whilst I
>> haven't read them in detail this seems to confirm the chip can be zapped by
>> lightning. We recently experienced a very close thunderstorm here so it
>> all appears to fit into place.
>>
>> The chip in the FT1kMP is a Maxim MAX232CWE. It is a discontinued product
>> but can be obtained from Farnell. There are two types with slightly
>> differing specs and I am trying to determine exaclty which one is best. The
>> package is a 16 SOIC, 16 pin DIL plastic surface mount. £3.35 or £2.57
>> depending on which version.
>>
>> The chip is Q5008 on the Control Unit board and is fairly easily
>> accessible. Remove top and bottom covers, with the radio upside down and
>> front panel
>> facing you, it is located rear left, immediately in front of the CAT
>> interface 9 pin D socket.
>>
>> Now comes the hard bit for many of us! You will need an SMD solder station
>> to change the chip! I ain't got one! Now I know why the Americans call it
>> "sodering!!
>>
>> Chris G3SJJ
>>
>>
>> ----- Original Message ----- From: "Chris G3SJJ"<g3sjj at btinternet.com>
>>>> To: "UK Contest Reflector"<uk-contest at contesting.com>
>>>> Sent: Saturday, August 21, 2010 6:15 PM
>>>> Subject: [UK-CONTEST] FT1kMP CAT problem
>>>>
>>>>>   I think already know the answer to this! I was playing around with the
>> SO2R set up today when I found I hadn't got serial interface between pc and
>>>>> the FT1kMP. The K3 was OK using  different USB to serial interfaces,
>> but neither would work with the MP. I was careful to check all the port and
>> baud
>>>>> settings. It all worked a couple of weeks ago when I checked it out.
>>>>>
>>>>> Logger32 Radio Debug shows no polling figures and the MP CAT indicator
>> doesn't flash.
>>>>> I guess the MP CAT circuitry has gone up the spout?
>>>>>
>>>>> Chris G3SJJ
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