[BC] 4MX-50 installation -- Third Installment

[gRAdy Moates]

    The 4MX-50 was put into the triplex antenna system at around 
1:00 AM today (Friday early morning).  

    It came right up into the common points with no adjustment from 
the settings already dialed in for both critical hours and day.  
With 22 kW forward I had about 40 Watts reflected (as indicated 
on the 4MX-50), and with 40 kW forward I had about 80 Watts 
reflected.  

    Without making any adjustments to the common point Z, 
we ran normal, symmetrical modulation and had no problems.  

    As I expected, with very heavy positive peaks and lots of 
presence boost in the audio, the transmitter's reflected power 
circuits were fooled into protecting the transmitter by throwing 
a fault and shutting down momentarily, but I've never seen an 
AM transmitter that could run heavily processed audio into 
loads like this without a little modification to the VSWR 
detection circuitry.  You should see the mods I had to do to the 
old 50 kW main xmtr at this site to allow aggressive processing.  

    Well, my deal with the BE guys was that I'd get the 4MX-50 
hooked up and ready to go, and test it into the dummy and 
the antenna to make sure there were no gross system errors, 
and then wait for them to come in to get her ready for her 
maiden voyage.  This I have done, so there won't be any more 
reports until they've been here to bless the installation and 
do some fine tweaks to the box in the field.  I'll post a few 
pix of the move-in after I get some sleep.  

    Oh, the first tune played through the box into the antenna system 
was "Hideaway" by Todd Rundgren from his CD "The Ever Popular Tortured 
Artist Effect".  It has a line in it that goes, "I'm trying to get a 
message through the air to you. . . get on my wavelength. . . and I'll 
show you which way to go. . . to my hideaway. . ."  

    Cool.  

Grady 

Grady Moates, Owner 
LOUD & Clean Broadcast Science 
voice  800 946-7007 
fax  800 529-5648 
email  grady at loudandclean.com 
website   http://www.loudandclean.com