[Tech-Assist] Moseley SL9003Q

[Bob Tarsio]

You could use a BDI DPS-100D outfitted with an N connector line section
which DOES measure digital power because it is an RMS sensor. Take a
look here: http://www.broadcast-devices.com/RFProducts.html

This power measurement system is capable of measuring digital or analog
carriers with a 50 dB dynamic power measurement range requiring no
slugs. Give us a call any time if you have any questions. 

Regards,

Bob Tarsio

www.broadcast-devices.com

-----Original Message-----
From: tech-assist-bounces at radiolists.net
 From: radioranger

>>Now, why didn't the Moseley TX LCD display indicate high VSWR?  Called
>>Moseley tech services.  The young punkin who answered (note: wear your
hip
>>waders when talking to this person) told me that they have a
circulator in
>>the transmitter output circuit and that the VSWR circuitry monitors TX
>>power
>>BEFORE the circulator.  

I second the thought about measuring the output of the transmitter with
a
Bird thru-line meter.  Because the signal isn't a continuous wave
carrier
the Bird will read a lower figure than you'd expect--- more like 3/4
watt
forward on the Bird for a displayed figure of maybe 1.25 watts on the
internal Moseley meter.

Of course you can also turn the slug in the Bird around to get some idea
of
reflected power, but with a 5 watt Bird slug you won't see very much,
even
if there is a problem with the line or antenna.

The other gotcha I ran into is a low received signal level on the
receiver
that may have nothing to do with the line or antenna.  In my case
something
was going south in the first stage of the receiver, before the signal
level
meter, that dropped the level from a normal -58 dBm to about -78dBm.
Replacing only the first module (the one with the N connector) took care
of
that problem. 

A spectrum analyzer, directional coupler and tracking generator are
still
the best way to troubleshoot these problems.

Steve Brown
Radio Rangers
Minneapolis