the SWR CAL knob on your radio works exactly the same as the "SET ADJUST" knob on your TR-1000.
its job is to calibrate the SWR meter so that the reading will be accurate.
you ALWAYS re-calibrate an SWR meter any time you check your SWR.
your 29LTD has a built in SWR meter, and yes, we could have done the whole antenna tuning thing by connecting the antenna directly to the radio and using its SWR meter.
the reason an external meter is better is because they are more accurate, and much easier to notice small changes on.
if you want to do a quick test of the radio's built in meter, to see if it matches what the external meter is telling you, just do an SWR reading on the external meter just like i showed you in the last post.
now, without changing anything else, set the switch on the radio to CAL, key the mic, and adjust the SWR CAL knob on the radio so the needle aligns with the mark on the meter labeled CAL.
unkey the mic, switch the switch on the radio to SWR, key the mic, and compare the readings on the radios meter to the reading on the external meter.
the SWR CAL knob on the radio is only for the meter on the radio and will not do anything to the external meter.
ok, before i continue; that antenna looks to be ok for what you want to do.
ive never used one, and dont know how well they are built, but if it works the way its supposed to, it should be fine.
dont forget to give the antenna the 90mph test!
you have to find out if that magnet mount will stay on at high speeds.
you dont want it falling off and hitting another car.
also, the location you have chosen to mount your antenna will result in a radiation pattern that favors the front of the vehicle.
what i mean by that, is that you will get out further in the direction your vehicle is facing, and wont get out as well towards the back of the vehicle.
if you put the antenna in the center of the roof, you will get out well in both directions.
now to pick up where we left off:
you have just set the SWR of your antenna, and still have the meter hooked up in line between the radio and the antenna.
turn the switch on the TR-1000 to the position marked "30".
this is the 30 watt scale on the meter. if you look just under the numbers going from .3 to 1000, you will see another set of numbers going up to 30.
use this scale when reading the output of just a radio, and use the position marked "1000" when reading the output of a linear amp.
that makes sense doesnt it?
now, key the microphone and note the wattage reading.
most likely it will be somewhere around three to four watts.
turn the DYNAMIKE (mic gain) all the way up. (BTW, unless your radio has been modified, you should always leave the DYNAMIKE all the way up. it doesnt really increase your talk power, it just decreases it if you need to for some reason, like checking your SWR)
now key the mic, and, with your mouth about 1" away from the mic, say, "TEEEEEEESSSSSST" for long enough to get a reading on how far the needle on the TR-1000 swings to the right while you are speaking.
(FYI, you should always talk with your mouth about an inch away from the mic for best audio)
what you have just measured are your "deadkey" wattage, and the "swing" of the audio.
write these numbers down and tell me what they are, phrasing it this way:
"my deadkey was X watts, and the swing was XX watts."
now for the amp hookup.
there are way too many variables involved in setting up a linear amp in a car for me to go over in one thread. the amp may have a high SWR for some reason, it might mess with the vehicle's computer, etc...
RF is a finicky beast to say the least.
i will tell you how to hook it up, and if problems arise, you might have lots of reading and learning to do to get it to work right. ok?, ok.
so, first pick where you want to mount the amp.
my suggestion is to mount it within a few feet of the radio, in a place that will allow air to pass over the heatsink fins.
run the positive wire from the amp directly to the positive terminal on the battery, and be sure to adequately fuse the wire right at the battery to prevent fires.
if the wire length is 10 feet or less, you can use 8ga. wire.
if the length gets over 12 feet or so, you should step up to 4ga. wire.
car stereo places have the right stuff, and will also have the correct fuse holder.
keep the ground wire on the amp close to a foot in length, and really try not to go much over that.
you need to find a REALLY good ground to mount the ground wire to.
sometimes a seat bolt will work, but many times these bolts have glue or adhesive on them, and dont make a very good connection with the chassis of the vehicle.
you may have to drill a hole to get a good ground connection.
just be careful not to drill into your gas tank, transmission, etc... LOL
whatever location you choose, you will have to sand off some paint and make the connection all bright and shiny metal to metal.
try to find some pics on the net of how others have done theirs.
now to connect the amp inline with your radio and antenna.
disconnect all cables from the radio and the meter and start from scratch.
connect a coax jumper from the back of the radio to the connector on the TX250 linear amp that is labeled "IN" or "RADIO" or whatever.
connect a coax jumper from the TX250 connector labeled "OUT" or "ANT" or whatever, and connect the other end of this coax to the TR-1000 meter where it is labeled "IN" or "RADIO" or whatever.
now connect the coax from the antenna to the TR-1000 meter where it is labeled "OUT" or "ANT".
now we are going to check the SWR going in to the amp, and the SWR coming out of the amp, so to speak.
first, start with the radio on, and the amp OFF.
set the radio to channel 20, and turn the DYNAMIKE all the way down.
set the TR-1000 switch to "SWR SET", key the mic and calibrate the meter the same way we did before.
now switch the TR-1000 to SWR and key the mic. note the SWR reading.
it should not have changed much at all from when you checked it without the amp inline.
if it did, you have an installation issue and need to go back and re-check all your steps.
we are about to turn the amp on, but before we do, you need to understand that this amp has different power levels, and by pushing certain buttons, you will get different levels of power. find a manual online to learn about how to select the power level you want.
right now we will leave it on HIGH, which is all buttons out except the red one, which is the power switch. the white button is a receiver pre-amp and will increase the receive gain of your radio. it will not affect the power output of the radio or the amp.
i find that these pre-amps just increase the noise level and dont really use them.
so, with the amp on, re-calibrate the TR-1000 and check the SWR.
you will notice that when adjusting the needle during calibration that the needle is much more sensitive to knob movement. this happens when using more power.
the SWR with the amp on should not be over 2.
if it is, you have problems, and need to keep your mic key ups very short while trying to fix the problems.
dont try to talk using the amp until you get the SWR down below 2.
now we are going to check the SWR coming in to the amp.
with the amp inline and on, calibrate the SWR meter in the radio, and check the SWR on the radio's meter just like we did before.
this reading should also be below 2.
if both readings are below 2 then you are ready to rock!
now switch the TR-1000 to the 1000 position and check your deadkey and swing wattage with the amp on. (dont forget to turn the DYNAMIKE back up!)
make a note of all these readings and post them as you go through this procedure.
we will look at the numbers you are getting for both wattage out and SWR readings, and go from there.
make sure to actually write down all these numbers, dont just try to remember them. LOL
good luck,
LC
