View Single Post
  #7  
Old 08-07-2017, 10:47 PM
Electronic M's Avatar
Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,762
Both the AM-40 and AM-60 series as well as the BAVM-Z series can transmit a decent distance. They all seem to work best around channel 7 and worst around channel 2. You need a dipole cut to the midband wavelength of the channel your using (shango66 has a good youtube video on that) for best TX distance.

With such an antenna and using channel 7 I get a full power 1 block radius with the 60 and ~200' radius with the 40 the BAVM-Z falling in the middle....Which makes sense if you look at the output power (dBm) specs of the three.

If you live in europe or a non-NTSC region don't import NTSC units from the states. Our channel assignments, modulation schemes and audio carrier offsets will not necessarily match those of other broadcast standards in a usable manner. I don't know if BT made modulators for foreign standards, but if you live outside the USA make sure the broadcast standard of your box matches your TVs.

Dave, it sounds like your box(s) were defective. These units are hard on lytics...I recapped a BAVM-Z with good testing used caps, and ~1-2 years later those caps are going bad too. Some of these units occasionally blow power regulator chips and or diodes. It is wise to google the regulator part numbers during repair. ID the regulator output voltages and pins and confirm voltages are on spec....Even if the lytics are good if B+ is low the units will not perform properly.
__________________
Tom C.

Zenith: The quality stays in EVEN after the name falls off!
What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
Reply With Quote