RFI-EMI-GUY
Member
- Joined
- Dec 22, 2013
- Messages
- 6,859
Ok;
I have set up my test bench to properly align some Systems Sabers. I have the proper RTK4203 cable I have used for decades to program these and make small adjustments, frequency, deviation and power. Never had a concern before. I am going to be adjusting the UHF radios all to full specs including modulation compensation which is out of wack on at least one radio. If I am doing one, I might as do them all and do it right.
So now I have moved the DOS computer and associated gear to my main desk where I have an HP8920B service monitor, RTX4005B test box, a proper HP remote sensing 7.5 VDC power supply, an RTL4224A battery block. All should be well.
First thing I notice upon making a test, by keying a VHF radio, is that the RF gets into my computer speakers, my nearby field strength meter deflects. So I look at the wattmeter, all good, the power is normal. VSWR is zero, the load is well connected.
On the VHF radio I can hear NOAA radio loud and clear, even on dummy load. Which is odd, because the transmitter is quite distant.
So I connect a UHF radio, Same results, less interaction with speakers, but the field strength meter deflects. So I disconnect all of the test equipment and attach a battery. Still the RTK4203 cable sprays.
I check the connections with a VOM, the RF coax has good continuity from the radio end to the wattmeter. The shield and center conductor good. I polish the gold terminals. Same issue.
So do these RG174 Teflon cables really spray that much power? I have never noticed before because I have had the set up quite a ways away from my computer speakers and field strength meter.
I have set up my test bench to properly align some Systems Sabers. I have the proper RTK4203 cable I have used for decades to program these and make small adjustments, frequency, deviation and power. Never had a concern before. I am going to be adjusting the UHF radios all to full specs including modulation compensation which is out of wack on at least one radio. If I am doing one, I might as do them all and do it right.
So now I have moved the DOS computer and associated gear to my main desk where I have an HP8920B service monitor, RTX4005B test box, a proper HP remote sensing 7.5 VDC power supply, an RTL4224A battery block. All should be well.
First thing I notice upon making a test, by keying a VHF radio, is that the RF gets into my computer speakers, my nearby field strength meter deflects. So I look at the wattmeter, all good, the power is normal. VSWR is zero, the load is well connected.
On the VHF radio I can hear NOAA radio loud and clear, even on dummy load. Which is odd, because the transmitter is quite distant.
So I connect a UHF radio, Same results, less interaction with speakers, but the field strength meter deflects. So I disconnect all of the test equipment and attach a battery. Still the RTK4203 cable sprays.
I check the connections with a VOM, the RF coax has good continuity from the radio end to the wattmeter. The shield and center conductor good. I polish the gold terminals. Same issue.
So do these RG174 Teflon cables really spray that much power? I have never noticed before because I have had the set up quite a ways away from my computer speakers and field strength meter.