[SBE] Thales Ultimate Transmitter

[Henry's dogs and cats]

First, check the channel range switch on the side of the modules. It is 
a small rotary switch near the edge of the cards.   Next, what is the 
transistor currents?   T1-4 are typically 12-16 amps, T5 typically 4-5 
amps and T6 3 amps.
At average drive levels, you should get 400-600 watts per module. At 
1250 with 4 modules, you are not getting what you should.  Again, go to 
the  IPA screena nd check the individual modules currents.  If any are 
significantly low, you have lost a transistor or two or four.   The 
currents between the same modules on each amp should be similar, 
typically not more than 2 amps different, ie 12.8, 13.5, 14.6, etc.   
If they are over 16 or under 12 you likely have an issue.   Check the 
dummy loads for each module.  Mine were onthe right side hidden behind 
sheet metal., You can take each out and measure 50 ohms, (coolant not 
running)    We found I had 1/3 bad on a 10 kw rig after 5 years.   What 
is your VSWR indicate?  ANy temperature alarms on the amp modules?  The 
PS units should be warm but not hot. Mine had 20 amp fuses and ran at 
14-15 amps. Usually the PS units go with a flash bang as they burn up 
and die.  We also found on our 480V 3 phase system, the unit weas 
unhappy at the rated input voltage of 480, dropping it to 470 made the 
modules last a lot longer.    Drive level is in the milliwatt range, I 
am guessing you don't have a balance and phase line/rheostat on your 
rig with only 4 modules.  Latly, if you have an RFA 300A or better, 
what is your constellation look like with correction on/off? (EQ) If 
the higher levels are all bent out of shape, likely bad power modules. 
Also, do a EQ setup (auto correct) because the RF feedback at the other 
station may have put it out of range.   ANy further questions, my rate 
is $250/day.

Regars
Henry Ruhwiedel




-----Original Message-----
From: Humphrey, Richard A <rhumphrey at kmaxtv.com>
To: sbe <sbe at sbe.org>
Sent: Tue, Jun 28, 2011 4:26 pm
Subject: [SBE] Thales Ultimate Transmitter



Anyone have a Thales Ultimate solid-state ATSC transmitter?  I’m 
working on getting ours going after it was loaned to another station.  
I’m concerned about the current consumption.  The two power supplies 
for the four PA modules are drawing about 18 amps each.  They are fused 
at 20 amps and the feed breaker is 40 amps.  The fuseholders are 
getting very hot after just a few minutes of operation.  I’m sure they 
would burn if left on long term.
 
How many amps does a working transmitter draw?  Thales tells me the 
output should be 1250 watts.  Anybody disagree with that?  What should 
my station load Bird indicate?  Am I overdriving this thing?  Where 
else should I look?  Thales has run out of ideas.


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