BCD325P2/BCD996P2: Low band reception?

[Randyk4661]

Does anyone else have problems with low band reception using the stock telescoping antenna?

With the telescoping antenna I can't pick up local CHP here in Southern California. It works fine on all the other bands.
When I connect to an outside antenna, I can pick up everything within 5 counties even San Diego which is about 200 miles away.

 

[tvengr]

Does low band work on the outside antenna? A 40 MHz 1/4 wave antenna needs to be about 6 feet long. The antenna on your scanner is only about 2 feet 3 inches.

 

[cmdrwill]

Correct you need a 70 inch long antenna.

A. Vertical Monopole Radiating Element (λ*0.25)*vf 70 inches long.

 

[jonwienke]

It's the wrong tool for the job. You could extend the telescoping antenna by clipping a piece of copper wire to the end, but that would bork reception on other bands.

 

[Randyk4661]

Low band works great on the outside antenna. With the CHP using repeaters and I'm only trying to receive the local office which I have done before on other scanners with stock telescoping antenna, I find it strange I can't receive in a major metropolitan area.

 

[jonwienke]

You're using an antenna with 20dB or more of loss due to it not being resonant on the band. You're going to have reception issues unless you're very close to the transmitter.

 

[ka3aaa]

The way this works is the lower in frequency you go the longer the antenna must be, the higher in frequency the shorter the must be. Get an antenna that is designed for the band which you would like to revieve.

 

[tvengr]

That is correct. The length of an antenna is inversely proportional to the frequency. If you double the frequency, you halve the length of the antenna. If you triple the frequency, the antenna is 1/3 the length. The whip antennas for the 27 MHz CB radios are 108 inches or 9 feet. To be totally accurate, the actual whip is 102 inches plus the length of a 6 inch spring..