In a message dated 1/22/00 2:18:39 PM Pacific Standard Time, [EMAIL PROTECTED]
writes:
<< Can anybody tell me a practical reason that it is not legal to change
crystals? I can't think of one.
And while you're at it can anybody tell me what it is like to be
gruntled?
And while you're at it, can anybody tell me, if I want to go up in size
from an HLG to a larger one, should I work my way up in size or just go
whole
hog and go standard or larger? I would rate myself as a low intermediate in
flying.....which planes?
Rodger >>
===================
CRYSTAL CHANGE:
Change crystal should be guided by FCC certified technican guided by original
manufacturer technical notes. Some but not all crystal swap may be made in
field by non-certified personels. The regulatory FCC concern about Tx crystal
from interference standpoint while your insurance service care about swaps in
Tx and Rx from potential link quality and risk of accident standpoint. Just
about everything we do in RC, make no error that the regulatory and service
do not connect our acts into false assumptions and negligence, if not ill
intentions.
The impression of changing crystal (channel element) to achieve channel
selection perfectly OK came from early days where everyone within the same
field (domain) is sharing a single original equipment design. Example, WWII
wireless equipment; US civil braodcast equipments. In other words, crystal
swap assume OK in common original equipment type. Not knowing that assumption
lead us in thinking that crystal swap may be made OK cross type. That put us
at risk of RF frequency offset that may post a harm to adjacent channel
interference problem to and from between adjacent channel Rx and Tx. If the
cross type crystal swap proves OK, that is not by design but by chance. The
next question will be is it up to the RC-ers to determine OK or up to the
licenced personel? Good Luck in your crystal swapping.
YK Chan
Seattle area.
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