Hi
Could someone recommend an affordable meter for testing two way radios broadcasting in the 70-90 Mhz frequency range. I mostly want to confirm the antennaes and cables are doing what they should be doing. I think radios are set at 5 watts output. (I need to do more than just an ohmmeter test on the 50 ohm coax shield and wire.) The system also uses a repeater which I would also like to diagnose. Not sure what the output power of repeater is.
Thanks for any recommendations.

 

RTL-SDR and the free software packages might do for signal strength, and of course
demod.

https://www.rtl-sdr.com/

https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20200321022438&SearchText=rtl2832

Or use a field strength meter, DIY, look at amateur radio handbook - https://archive.org/search.php?query=amateur radio handbook


Regards, Dana.

 

I doubt that you will have problems with your coax being too far off impedance-wise if you are using new coaxial cable.

An ohmmeter measures resistance, not impedance. You can probably rent a network analyzer for that.

 

Antennas, coax feederlines etc may be VERY accurately tested by 50$ Nano-VNA (e-bay, Wuhan factory no somewhere else but China). Ensures the one port-tests and two-port tests but not at active line.

 

Dick: Why to rent anything what will cost probably 50 bucks if may buy it for the same 50 bucks?

 

Excellent! I did not know such things existed. The last time I was around gear like that the price was many thousands, but that included the pen plotter and the floppy disc with the DOS-based software.

 

Hi
Could someone recommend an affordable meter for testing two way radios broadcasting in the 70-90 Mhz frequency range. I mostly want to confirm the antennaes and cables are doing what they should be doing. I think radios are set at 5 watts output. (I need to do more than just an ohmmeter test on the 50 ohm coax shield and wire.) The system also uses a repeater which I would also like to diagnose. Not sure what the output power of repeater is.
Thanks for any recommendations.

A handy instrument would be a field strength meter.

You should be able to build one like this.

http://www.k2gq.org/init/static/files/RF_Field_Strength_Meter.pdf

An off-the-shelf unit like this would cost around $ 25.00.



- Nandu.

 

For field strength meter far more accurate data are giving the same price digital wonders TM195 (50 MHz-3,5 GHz) without of spectral analyzer and Go_EMF-390 what is zero Hertz to 10 GHz with in-built spectrometer (however only up to 2,5 GHz).

 

PS
Third option - the Digital Defined radio like blue 5$ SDR working 3 MHz-1,7 GHz or it 40x expensiver twin the Hack-RF-1 working 50 kHz-3.5 GHz. Just You see in the real tome ALL signals in spectrogram antenna is able to see, OKay You have no validated accuracy on signal stregth except the ratio between signals. However approximate signal strength is known there. However there are a just nightmare about right computer interfaces installing. Yet I am sure witness, it is possible.