[Elecraft] XV50 cooling

[Don Wilhelm]

Geoff,

I do not have proper equipment to do a true noise figure measurement, 
but my signal generator will go down to -140 dBm, and I can give the 
number of dB above the receive noise floor for that signal strength - I 
can do that at various temperatures during the other tests.

I doubt the temperature rise will affect the active devices, but a 
change in temperature *could* alter the inductors a bit which could 
detune the input circuits slightly.  At this point, that is all speculation.

73,
Don W3FPR

Geoffrey Mackenzie-Kennedy wrote:
> Don,
>
> I do not like to add to your workload, but I would be interested to know if 
> the heat generated by the Mitsubishi power module has any negative effect on 
> the transverter's noise figure (receive mode) if you have the time to 
> measure it. If I understand the layout of the XV50 correctly, the input 
> circuitry of its receive path is placed quite close to the power module.
>
> My reason for asking is that I have been considering the option of buying a 
> XV50 for use in a set up dedicated only to 6m EME, rather than building a 
> transverter from scratch
>
> 73,
> Geoff
> GM4ESD
>
>
> Don Wilhelm wrote on Sunday, June 06, 2010 at 3:59 AM:
>
>
>
>   
>> Gentleman,
>>
>> My promised temperature rise measurements will have to be delayed a
>> bit.  This XV50 has a bad power output module and I will have to wait
>> for one to be sent from Watsonville.  Later next week, I will have the 
>> data.
>>
>> BTW - Mitsubishi in their notes at the end of the data sheet suggest
>> that the module case temperature should be limited to 60 deg/C - but
>> that is "too hot to touch" (140 deg/F), so the "excessively hot"
>> criteria may actually be well within the limits of tolerance - I would
>> not want to hold my hand very long on a surface that is at 60 deg/C.
>> Also, I do agree that other components can be affected by the
>> temperature rise, but most are spec-ed at 60 deg/C, so in reality, there
>> may be no problem, just a "discomfort zone" - details after the new
>> module arrives.
>>
>> 73,
>> Don W3FPR
>>     
>
>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>