who's right?

[fsthawk]

Ok, I have a RFX 75 bought from a shop that sells them but won’t install them (to much work).
Shop “A” says on the 29 it will walk the dog , but would be worthless on the 949.
Shop “B” says it’s a killer on the 949, but will kill the 29

Which is more correct and who should I stay away from and why?
Don’t want to talk across the state only the bay.

 

[Robb]

Neither.

It is just an amp. Just 75 watts peak envelope power ('PEP'). It shouldn't kill anything. In fact, beware of the shop that gets more power out of it than 75 watts and tell you it will last a long time that way.

You don't need 75 watts to talk skip. I've talked all over the US with just a stock radio and a beam antenna - and did it well. To talk locally across a certain distance from point-to-point, you need to make sure that your antenna is doing the talking. Not necessarily using more power. The ANTENNA is the real heart of any radio station. Do all that you can with the antenna to get the best line-of-sight between the two points. If you need to put it up higher and it still doesn't work the way you need it to work; then adding more watts/power should then be considered.

Getting more than 100% modulation out of any radio is ultimately to the detriment of the transmit clarity. If either shop clips the AM limiter and disables the 2nd harmonic filter -in either radio- in favor of a nasty-sounding transmit with higher output ('peak and tune'); then find a shop that knows better . . .

 

[Black_Bart]

yup, Robb is correct, i talk skip all over the USA/Canada/Mexico & Central & South America, the EU and Australia on a 15 year old barefoot 2950 i switch between an A99 or a horizontal dipole made from two 102 inch steel whips, and it PEPs out at 20 to 25 watts, i have the radio set so when i turn the RF power knob down it TXs only 1 watt and i can talk all over the county locally on only 1 watt, sure the big dogs can cover me up but i am not about competition for the most powerful, i mostly just listen to radio about 99% of the time anyway

 

[binrat]

My 2 cents, if the radio has it installed at the factory then ok. If you want to install it then get a small external amp.
The antenna is the most impotant part of your system, them good quality coax, then the radio, then the mic.
Have to agree with Robb regarding the shops.

 

[9C1Driver]

I would agree, both your "shops" are full of it. The RFX unit's are just small amplifiers that mount on the back of the radio. They work well on radio's like a Cobra 29, when done right you can see 100-110 peak watts. On SSB radio's they only do 70-80 watts. There is really nothing in the RFX unit that makes your radio a "killer". Now when you combine some audio mods with it your talken.

Get in touch with this guy, he does lots of custom mods and is excellent with RFX installs.
Site Disclaimer - Custom CB radios

 

[psycho]

Buy either radio and a 150 watt amp, you'll be MUCH better off.

 

[unit_399]

Buy either radio and a 150 watt amp, you'll be MUCH better off.

Ditto or ... get an RCI2970

 

[cbradiomagazine.com]

I'd agree that the best solution would be the external amplifier solution - something like the KL203 is on sale for $50 right now and will do more wattage than the RFX75 and will work perfectly on either of those radios.

As far as your original question - from what I've heard people have had better results with aftermarket installs of the RFX75 in Cobra 29's than SSB radios.

 

[BammBamm]

Another nod to Robb. Soon after I joined this site I DX'd on a Galaxy dx949,50 foot of LMR400 and a home made horizontal dipole and talked from the South side of Chicago to Robb in California. My amp has remained disconnected ever since. I was waiting for my new antenna and couldn't wait so I made my own dipole. I do run a 257HP which has the rfx on it but mainly got it for the features and ability to get over the locals. I am actually going to sell it and buy a RCI 2950DX soon. If power is a must get a KL-203 it's cheaper and more powerful. Just my 0.02