forward / reflect on a 10k????

[tonyhatchetman]

got my bird meters in and a dual line section put them on my setup so heres the ? got a 5000 w slug going out and a 25 going back and with my 2,4,16pill on i get like 500 dk and 1800 forward and on the 25 w in reverse it shows 17 watts at the( 500 dk) and it falles back to 12 when it swings .....this is when im still but going down the road it shows 40 at the dk and falls back to 20-25ish useing a 100watt slug ..........is this too much reflect???

[wrong way]

got my bird meters in and a dual line section put them on my setup so heres the ? got a 5000 w slug going out and a 25 going back and with my 2,4,16pill on i get like 500 dk and 1800 forward and on the 25 w in reverse it shows 17 watts at the( 500 dk) and it falles back to 12 when it swings .....this is when im still but going down the road it shows 40 at the dk and falls back to 20-25ish useing a 100watt slug ..........is this too much reflect???

wow that sounds great to me thats like 1.2:1 isnt it? I get bout 1/2 that reflect with like 1/4 of the the pills. but I dont know this could get interesting

[jessejamesdallas]

If what your saying is you have a "Backward swing", that usually means you have your DK set too high on the radio..."What is your DK on the radio?"

Or, the Amps are starving for more power....

[tonyhatchetman]

If what your saying is you have a "Backward swing", that usually means you have your DK set too high on the radio..."What is your DK on the radio?"

Or, the Amps are starving for more power....

i have 2 bird meters one dual line with a 5000 w slug for froward and a 25 and 100 for reflect and the reflect shows the 17 to 12 ..........at the same time the first meter shows the swing

[jessejamesdallas]

Your probably OK...I would PM North Texas Mudduck and ask him. He runs Bird Meters, and a set-up like yours. He would know for sure.

[tonyhatchetman]

k thanks jjd

[1iwilly]

If what your saying is you have a "Backward swing", that usually means you have your DK set too high on the radio..."What is your DK on the radio?"

Or, the Amps are starving for more power....

i have the same problem on my 1x4 i have it dead keying 200watts rms swinging bird rms forward to 375 watts my reflect on a 25 watt slug is 7 watts and when i add audio it goes down to 3 watts rms swings forward reflect swings backward.

[Red Warrior]

If what your saying is you have a "Backward swing", that usually means you have your DK set too high on the radio..."What is your DK on the radio?"

Or, the Amps are starving for more power....

i have the same problem on my 1x4 i have it dead keying 200watts rms swinging bird rms forward to 375 watts my reflect on a 25 watt slug is 7 watts and when i add audio it goes down to 3 watts rms swings forward reflect swings backward.

The calibration on most Power Meters requires steady state power (unmodulated). This is why you do not speak into the microphone. Modulating the carrier will cause power to fluxuate and calibration will become impossible. Once the meter is calibrated SWR can be read accurately. Modulating the carrier after the meter calibration point has been set will result in the meter giving random SWR readings.

[127]

If what your saying is you have a "Backward swing", that usually means you have your DK set too high on the radio..."What is your DK on the radio?"

Or, the Amps are starving for more power....

i have the same problem on my 1x4 i have it dead keying 200watts rms swinging bird rms forward to 375 watts my reflect on a 25 watt slug is 7 watts and when i add audio it goes down to 3 watts rms swings forward reflect swings backward.

The calibration on most Power Meters requires steady state power (unmodulated). This is why you do not speak into the microphone. Modulating the carrier will cause power to fluxuate and calibration will become impossible. Once the meter is calibrated SWR can be read accurately. Modulating the carrier after the meter calibration point has been set will result in the meter giving random SWR readings.

Huh????? They are reading a Bird 43.

[Red Warrior]

If I use a Bird 43 and the forward is 100 watts, then I measure the reverse and it is 2 watts, I can plug the values in a formula and calculate SWR.

If I modulate the forward and it is varying from 100 watts to 430 watts and I switch to reverse and it is varying from 2 watts to 47 watts how do I plug the range of variables into the formula to get a realistic SWR calculation? I guess we could use an integrated calculus function. I might believe you could get close if you used a audio tone generator directly into the radio so your audio level was more constant. Most folks I have observed attempting this sing aaaaaauuuuuuddddddiiiiiiiooooo into the microphone. They are usually disappointed with the results. Most often they are trying to read peak power and just for grins are attempting to look at SWR at that same power level.

Try this with a dual needle meter. Modulate and watch the needles swing all over the place.

The only accurate way to measure SWR with a power meter is when the RF is in a steady state (dead key).

My technicians tell me there is an exception to this and it is called a digitial sampling power meter. The only reason it works is because it takes a snapshot in time and measures both forward and reverse at that microsecond interval. A little expensive however. They keep telling me I need to buy them one.

And after all this effort what does a SWR during modulation actually tell you that dead key didn't? The resonance of an antenna doesn't change during modulation, only your ability to measure it.