Testing a new VHF aerial

[lw395]

Firstly determine the construction of the antenna, some are described as DC grounded, if so a resistance value should be specified. With the antenna connected to the cable, remove the plug from the radio, select the appropriate scale on the multimeter and place 1 probe on the centre pin, the other probe on the outer, the meter should indicate the resistance 10,000 ohms in the case of the Hawk. Note that the check should never indicate a short i.e. no resistance.

There are lots of aerials out there with very low dc resistance to ground.

 

[lw395]

resistance is d.c. impedance. Impedance is frequency dependent.

Strictly, resistance is the real part of impedance. It may be frequency dependent....

 

[IanR]

Just wanted to express my thanks to Martin who gave up his time to come out to the boat on Sunday.

Martin taught me the correct way to use an SWR meter and brought his box of bits and tools and helped me diagnose a faulty length of cable inside the boat betwixt radio and mast foot. He then built me a short length with two connectors and tested with exceptional transmit and receive clarity.

I cannot thank him enough, although I hope some wine might help a bit. He is an exceptional teacher and a credit to the forum.

When the forum awards come out I and others would certainly vote for him.

Martin the ocean nav offer is definitely on