need help from 148 gtl experts

[1iwilly]

hello to all

i'm having an odd problem with 1 of my radio. here is the problem with my 29 classic my reflect on my box is ok with my 25 classic it is also ok no issues but when i run my 148 gtl philly made i have a higher reflect 29,25, relect=5 watts on a 600 watt dead key

with the 148=12 watts then it starts to creep up a little. tech look at the box no issues found check coax no issues found. clean all ground. no luck

 

[RatsoW8]

You didn't give us much info here to go on. If the input to the amp is exactly the same from the 148 as the other two radios the output and swr should be the same. The amp can't tell one model from the other. All it basically sees is input power. You would need to test the 148's output without the amp out of the line to see if that's the issue.

You would need to detail the entire system from radio to antenna to get a good answer.

 

[mackmobile43]

Place your power meter inline between the radio and the amp as close to the radio as possible, a double mail pl-259 works great for this and use a half wave of coax which is dependent on the coaxes velocity factor.

Using this SWR CALCULATOR you can determine if your radios input varies into the amp .

You'll also need a dummy load that will handle your amps output, not an antenna.

 

[1iwilly]

Place your power meter inline between the radio and the amp as close to the radio as possible, a double mail pl-259 works great for this and use a half wave of coax which is dependent on the coaxes velocity factor.

Using this SWR CALCULATOR you can determine if your radios input varies into the amp .

You'll also need a dummy load that will handle your amps output, not an antenna.

when i check it that way with a swr meter i get 1.4 swr.???

 

[mackmobile43]

when i check it that way with a swr meter i get 1.4 swr.???

are you using the swr bridge in your meter or using the calculator with your output power and reflected wattage, don't trust the meter's swr bridge.

 

[1iwilly]

are you using the swr bridge in your meter or using the calculator with your output power and reflected wattage, don't trust the meter's swr bridge.

well 600 watts dead key and 5 watts reflect= 1.2 swr
i use an external meter i never use the internal meter in the radio

 

[mackmobile43]

well 600 watts dead key and 5 watts reflect= 1.2 swr
i use an external meter i never use the internal meter in the radio

You're still not understanding, the reflect you use for this test is from your radio and not the amp. you want to know what your radios are seeing into the amp.

 

[mackmobile43]

Example: Online Standing Wave Ratio Calculator
V1.1 By Allen D. Kass © 2000
=====================================
Forward Power = 5 Watts
Reflected Power = 1.5 Watts
Standing Wave Ratio = 3.42

Put the external meter behind the radio, key the radio and get your forward avg watts and then the reflected wattage and enter that into the calculator and you'll see what your radio sees into the amp and you'll either find fault with one of your radios or the input tuning of the amplifier.

 

[1iwilly]

Example: Online Standing Wave Ratio Calculator
V1.1 By Allen D. Kass © 2000
=====================================
Forward Power = 5 Watts
Reflected Power = 1.5 Watts
Standing Wave Ratio = 3.42

Put the external meter behind the radio, key the radio and get your forward avg watts and then the reflected wattage and enter that into the calculator and you'll see what your radio sees into the amp and you'll either find fault with one of your radios or the input tuning of the amplifier.

oh ok i got it now thanks