Re: mono band 2 meters rig based on the micro BITx circuit #ubitx #2meters

ajparent1/KB1GMX <kb1gmx@...>


LO chains for UHF.  Multipliers add noise so if phase noise is a fact at the fundamental output the 
phase noise of a 3x multiple is 10 log(3) worse!  For small values of N that may be fine but
wen N gets to 10 or more its painful.

If you  experience is FM and repeaters none of that applies to SSB weak signal.  I work out to 15 miles
here from  repeaters using a BoFeng on 2 or 70-cm but the repeater has a 6 or 10 db lo angle
antenna on a tall hill.  With the 55W mobile and a simple 1/4 wave whip I've been heard 65 miles
away on the same repeater.

A good 432/435 SSB rig has a NF under a db for the lna and  SSB band widths can hear down
to better than  -147dbm.  Least mine do.  For 2M it only get a little better.  To work out to 100mi
with some degree of repeatability the set up is 160W, RX LNA, and a 11 element 3.7 wavelength
beam up 35ft from what some would call a good location.  UHF with 60W and a 15 element beam
the best shot to date is 68 miles.     For 6M the game changes as a 5 element beam and 160W
gets me the world at times.  6M has Eskip aka sporatic E, ducting, and Aurora, during the open
season I've worked 3000+ miles (Eu countries) using 4W and a square loop. It was much easier
with 100W and a 3 element beam.  The same mobile setup under average conditions 60 miles
to a very good station with beams on a tall hill.   For comparison a similar radio to the 6M HB
on 10M during the 2009 solar minimum got me 85 countries for far less effort.  I'm a  hard
core VHF/UHF person.  You have to want to do it.   I can say marginal radios especially
receiving do not make the grade.  FT8 mode or JT65 can improve things if all you want
is "contacts" not conversations. But then you need a tx chain that can support full power
out for up to 15 minutes at a time. 

Working the satellites is far different as then you looking 400-6000 miles depending on angle and 
your fighting  path loss and sometimes refraction.   SSB through translator sats is interesting but
requires both a good radio with simultaneous RX and TX on different bands so you can hear if
your making it plus total computer control to counteract doppler.  And aim the antenna.  For FM
sats (aka EasySats) two 'fengs a hand mic, a headset, and a simple hand held antenna well do fine


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