[NLRS] Future band plan for 9cm (3456)

[WA2VOI, Donn]

'Morning, Jon & NLRS
I took a look at the SBMS proposal and personally, I'm not impressed.

The use of 3398.1 does pose problems.  Assuming a 144MHz i.f. it produces a (politely 
worded) "difficult"  frequency as the LO. (3254 MHz).  Actually, its difficult only in 
that there's no off-the-shelf PLL LO that is currently programmed for it.  (Using XTALS 
for the  LO for either 3398 or 3400 w/144 i.f. results is fractional frequencies.  3400 
ends up at 101.75 vs 101.6875 for 3398.)  Those of us who have DEMI 3456 XVRTRs w/A32 PLLs 
can move to 3400 i.f. with a ONE WIRE ADD to the frequency jumpers.  Similarly, Q5 Signal 
has a PLL also programmable for both 33456 and 3400 with a change in the frequency 
selection.  DEMI 3456 w/Micro-LOs COULD re-crystal and then retune but with the price of 
XTALS it may be cheaper to go to and A32 (DEMI) or a digiLO (Q5).  Its  CERTAINLY easier.

Given the usage of ANY 9cm activity (low) and the activity of 9cm EME (low with-in the low 
category) I don't really see a problem using 3400.1 as a calling frequency for both 
activates (Yet, see below.)  Propagation on 9cm isn't like 2m where ducting and 
troposcatter make multi-100's of mile Q's common and would interfere with EME activity. 
It appears SBMS is solving a non-problem.  Yes, they cite "bring[ing] the United States 
into alignment with other worldwide Terrestrial and EME activity."  Is this really 
desirable let alone necessary ?

Moving to the terrestrial band to 3398-3400 increases the difficulty of supplying the LO 
necessary, which will reduce the number of current 3456 OP making the switch, which 
reduces even further the Amateur presence on the band.

Overlapping the terrestrial band w/EME MIGHT cause minor problems on occasion, but it has 
the potential of holding on to many of the current 3456 OPs.  Dividing the terrestrial 
band to, say, 3400.2 and UP, with 3400.2 as the calling frequency most likely would solve 
any of the problems.  ALL that takes is to turn the dial !!
[end rant]

73 Donn
WA2VOI/0





----- Original Message ----- 
From: "Jon Platt via NLRS" <nlrs at mailman.qth.net>
To: <nlrs at mailman.qth.net>
Sent: Wednesday, April 07, 2021 2:54 PM
Subject: [NLRS] Future band plan for 9cm (3456)


> Hello NLRS land. There is ongoing information and discussions regarding the future of 
> our 9cm band. It appears that the original doom and gloom prediction of loosing the 
> entire band to amateur radio use has changed (good news) and that we will be maintaining 
> a chunk of that spectrum at 3.30 to 3.45 GHz. This does mean that many of us with legacy 
> equipment will have to re-align them (if possible) from the current calling frequency of 
> 3456.100 MHz. There is ongoing discussion about what may be the best terrestrial based 
> weak signal calling frequency, either 3398.100 or 3400.100 MHz. The SBMS has posted 
> their thoughts on this subject at 
> https://w6ife.com/documents/3.4%20GHz/SBMS%203_4%20GHz%202021_04_02.pdf..73, JonW0ZQ
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