"joseph2010" wrote in message
...
I just read the following, and I'm wondering if it's true?

I use a CB SWR meter to check 2M antennas all the time. There is a
trick to it however.If all you want to to is check SWR on your 2M
antenna, you don't necessarily have to buy a dedicated VHF/UHF SWR
meter. What I keep in my toolbag for that is a cheapie $5 hamfest
special CB SWR meter. They really don't work well on 2M but there's a
trick you can do that will net a reasonably accurate SWR reading on 2M
with one of these meters.

What you do is connect up the meter as usual, key the rig with the
switch in the forward power position, set the adjustment for full scale.
Now, without touching anything, swap the coax connections so that the
rig is connected to the "ANT" side of the meter, and the antenna is
connected to the "XCVR" side. The reading you see on the meter will be
very close to your real SWR. The closer to 1:1 your SWR is, the more
accurate it will be. It would be more convenient to have a real SWR
meter or antenna analyzer if you do a lot of testing, but for a quick
antenna check after a mobile install or whatever, the $5 CB meters work
OK.

I'm not sure I believe this, what do you think? thanks in advance

For the meter you have, it is mostly true. I don't know if it is really any
more accurate,but it will work just fine. Usually when you get under about
1.8 or 1.5 to 1 that is close enough. The main thing is just to tune for
the lowest reflected power. As long as it is low enough the rig puts out
full power, that is the main thing in most cases.

Most any of the SWR or directional watt meters will work fine in either
direction. You can take the meter you have and hook it up the way you are
suspose to and see what you have. The reverse the coax. You also have to
keep it in your head the forward/reverse switch will work backwards. That
is you set it for reflected power and adjust for full scale. The switch it
to forward to read the SWR. That is one way to run a quick check to see if
the SWR meter is working like it should. You may see a small differance,but
should not be too much.

The meter you have has two coupling wires. One is used to measuer the
forward power and one measuers the reflected power. They should be
exectally the same. Those 150 ohm resistors should be exectally the same
also, but they are ofter eithe r 5 or 10 percent resistors. As with most
mass produced items, on line may be a fraction of an inch longer or closer
the the center line. This is not usually a problem. After all , this is
not a lab grade instrument. Even the much praised Bird meter is not really
that accurate if you read the specifications.

Watt meters are not normally needed to be super accurate. I have a service
monitor that origionally cost around $ 50,000. Bought it for under $ 1000
as it was mainly for the old cell phone stuff that is not used any more, but
it also works great for other servicing.

The frequecny readout is almost dead on. The specs is something like being
within 85 Hz at 850 Mhz. The wattmeter is still only rated for about 5%.