[BC] DTV out of band emissions

[Gary Peterson]

Robert,

Thank you for the reply.  Yes, the station is in Rapid City.  My home is
1.06 miles from their tower.  We were hoping that the high noise floor might
have been due, in part, to intermod between their analog channel 3 and their
digital channel 2.  We waited until June 12 for channel 3 to go dark.  No
change.  Even though the FCC's rules prescribe that spectral measurements be
made at the output of the DTV transmitter, we plan to look at their
emissions from a mile away with a decent spectrum analyzer, adjusted
according to ATSC recommended practice.    

Prior to that, I placed a Decibel Products cavity in front of my six meter
rig.  That helped but greatly restricted my ability to QSY.  Since that
time, I abandoned my homebrew, three element Yagi and built a vertically
polarized folded dipole.  This enabled me to work six again.  I am now
planning to go with a vertically polarized Yagi.  In the meantime, this has
affected about fifteen hams that used to work six meters.

I wonder if the station is having second thoughts about choosing channel 2
for DTV.  Virtually all the reception complaints I have heard, have been
about channel 2.  The other stations in the market chose RF channels 7, 16,
21 & 28.

With luck, they will reconsider and QSY up.  One can hope, anyway.

Regards,

Gary, KØCX

" Gary, If this is the station in Rapid City, you may have a problem. The
station is 7.5 KW or if you convert to dbm, it is about 67 dbm. The mask at
51 mhz must be 80 db down. That leaves -13 dbm or 20 mw legally radiated
near the bottom of the 6M band. From a good antenna on a high tower, that
gets out fairly well. The mask is pretty decent for adjacent TV station, not
so great for and adjacent ham band. "