[eagle] Re: CAN-Do noise abatement plan and questions

John B. Stephensen kd6ozh at comcast.net
Thu Jun 14 08:09:00 PDT 2007


Bob:

Were they tested sufficiently for radiation resistance? I'm assuming that 
the tantalum was used to add radiation shielding for things like flash 
memory on the MCU. Mirek's receiver also uses flash memory to store the 
frequency. The PLLs used in the existing 70 cm receiver can be purchased in 
a pin-compatible rad-hard version. However, the frequency has to be stored 
in flash memory. PIC MCUs hold data for 40 years on earth but space is a 
harsher environment.

We have the option of buying PLLs (with more pins) that can be hard-wired to 
a particular frequency. These PLLs are much more expensive and have longer 
lead times as they are space rated.

73,

John
KD6OZH

----- Original Message ----- 
From: "Robert McGwier" <rwmcgwier at gmail.com>
To: "Bill Ress" <bill at hsmicrowave.com>
Cc: <eagle at amsat.org>
Sent: Thursday, June 14, 2007 10:46 UTC
Subject: [eagle] Re: CAN-Do noise abatement plan and questions


> That they were not sufficiently tested by anyone who was to use them to
> build flight units.  This consumed tantalum slides, and lots of effort.
> Stephen got essentially zero feedback from the engineering test units he
> sent.  This noise issue could have easily been found.  They have had the
> engineering units for a LONG time.
>
> Bob
>
>
>
> Bill Ress wrote:
>> Hi Bob,
>>
>> Just curious - what were the "objections?"
>>
>> Regards...Bill - N6GHz
>>
>> Robert McGwier wrote:
>>> The Germans demanded their flight modules over the objections of the
>>> designers and manufacturers so they are on their own with the
>>> consequences.
>>>
>>
>>
>
>
> -- 
> AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL,
> TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair
> "If you're going to be crazy, you have to get paid for it or
> else you're going to be locked up." Hunter S. Thompson
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