• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • Click here to find out how to win free radios from Retevis!

tell me about FM please

wrong way

Member
Dec 3, 2008
16
0
11
44
columbus ohio
hello I gotta know every thing about theese cbs so I ask alot of ????? what about fm is it fun to mess with? are there any advantages? can I use my 1x4 fatboy on FM? can I leave my dosy in line? thanks in advance fellas for all the info.. and I forgot should swr stay the same? hope yall can clear this up for me thanks
 

Your Fatboy will work better on FM then AM. Don't expect higher output power though.There is no swing on FM either so don't expect to see the meters moving while your talking. SWR will stay the same as well and yes you can leave your Dosy inline. Nice thing about FM is its allot clearer and will not bleed through TVs and phones like AM.
 
Your Fatboy will work better on FM then AM. Don't expect higher output power though.There is no swing on FM either so don't expect to see the meters moving while your talking. SWR will stay the same as well and yes you can leave your Dosy inline. Nice thing about FM is its allot clearer and will not bleed through TVs and phones like AM.
thank you very much I been looking for an answer like that for a while seems not many know about fm. but know with what I know Im gonna give it a try thanks...
 
FM is very cool, it does generate alot of heat very fast though. I would run the radio with the power all the way down into the amplifer and just monitor it.
 
I would run the amp at about 1/2 of its max power for FM use or put a fan on the heatsink. It's a much higher duty cycle mode than SSB and indeed will heat the amp up fast.

From requiring best to worst conditions for a solid signal I would rate the modes as

FM
AM
SSB
 
The first time I tried FM on my old 2950, I had a contact with two guys in Canada, one on the west coast in British Columbia, and the other was on the east coast in Nova Scotia. I was in Illinois, running 10 watts. All three of us were copying each other Q5.
 
I have used FM for dx also on 11 meters, ooops I snitched myself out but just run the amp at it's rated output or just below so if you have 4/2879 finals in the amp keep it at 400 watts or less in FM mode and remember FM on 11 meters is illegal in the U.S.A. .lol

loldhr1.jpg
 
as far as bleed over problems go, i,d say there would be alot more with fm as it is alot more broad banded..
 
Last edited:
On 10m there are FM repeaters. When the conditions are right, I can key an FM repeater in Dallas from Los Angeles and broadcast to 1/2 the world :) :)
 
I used to work the 29.560/660 repeater in the US Virgin Islands from my mobile with 25 watts. From there it was anybody's guess where propagation took me. (y)

I had forgotten about that repeater! I used to listen to it sometimes before I had my General. Man, that thing used to boom in here in the midwest!(y)
 
On 10m there are FM repeaters. When the conditions are right, I can key an FM repeater in Dallas from Los Angeles and broadcast to 1/2 the world :) :)
I hope u have general class license when do that. Even if u do, broadcasting is a violation of the rules (ask Glenn Baxter).
Rich
 
From past experience and from example, I seriously doubt if I'm going to ask Mr. Baxter anything! ;) As for the 'broadcasting' thingy, you do that every time you call CQ. You aren't 'broadcasting' if someone answers you though, so no biggy. That's sort of being 'picky', but still a fact, oh well.
FM range is sort of "iffy". It depends on propagation and the band used. It isn't like other modes, but either a 'hear it' or 'don't hear it' thingy, not much of anything in between, never hear two signals at the same time, just a 'garble' when two signals 'mix'. Which is one reason you won't ever hear it for aeronautical communications, can't tell when a weaker station may be trying to call (or military for that matter, same reason).
I haven't heard a 10 meter FM repeater in a while. Lots of reasons for that, mainest one being I just don't listen very often. But, I have tried 'chunking' the freqs and no response. The VI repeater was really 'big' here too.
- 'Doc
 

dxChat
Help Users
  • No one is chatting at the moment.
  • @ Mark Malcomb:
    Hello BJ. Been a long time since I've been on. You doing well? Mark Malcomb
  • @ Naysayer:
    I’m
  • @ kingmudduck:
    Hello to all I have a cobra 138xlr, Looking for the number display for it. try a 4233 and it did not work