View Full Version : Constant SWR 3

12-18-2018, 05:01 PM

After many years I powered up My Alan 48 Plus.

I have problems with big swr. It is 3 on ALL channels.

I tried to adjust lenght of antenna but swr is always 3.

I use Alan K135 swr meter and antenna on pictures bellow.

Can anybody give me some advice how to fix that.

PS: Someone knows model of this antenna?


12-18-2018, 05:12 PM
i see rust/corrosion on the spring , probably has it on the coil or coax inside the coil housing . or you may have a short or corrosion in the coax . you can try to open the coil housing if it's possible without destroying the antenna to check them and clean/fix them ...... just a guess though

12-18-2018, 11:35 PM

Will try to clean rust with alcohol. I think coil couldnít be open.
For test I try to transmit for 1sec without antenna and SWR is stil 3. Not endless but 3.
This could be CB Station or SWR meter problem?

12-19-2018, 01:41 AM
Itís the antenna or the coax as said. Check for any pinches or cuts in the coax and also if possible check the spring coil for corrosion or a bad wire inside. That and the connector on the end of the coax. Donít transmit without an antenna hooked up as you can damage your radio. Also place the antenna on a large piece of metal before you use it. That or a vehicle if itís not. You canít use it just sitting on top of a desk. The antenna needs to be placed onto something large and metal like a car roof.

12-19-2018, 03:59 PM

Thank you all for help!

Just reassemble antenna (not the coil, that cant be open) and clean it with alcohol, I also put new connector on coaix and now swr is from 1.5 to max 2.

Thank you :)

Now I have another problem with lots of electrical brum in my voice when I transmit.:)


12-20-2018, 03:55 PM
Have you tried to tune the antenna? What are the VSWR readings on ch1, ch40, and ch20? You may need to make sure you have a good ground as well. This may or may not help with the transmit issue you are now having. Try grounding the chassis of the radio to a good known ground.