Which ham HF models can be modified for C.B. and Freeband transmit?

[kc0bus]

Hi,
Which ham HF transceiver models can be modified to transmit on the C.B. channels and also the Freeband channels?
Thank you

 

[jwt873]

Pretty well all the solid state rigs built since the 1980's can be modified. Some are easy, some are difficult. http://mods.dk has the and diagrams in a database. You need to sign up with them and they limit how much you can download. The more you 'donate' the more you can see.

Of course, you'd only be doing it as a matter of seeing whether or not it could be done and not actually transmitting out of band.. Right? (If you get caught, the fines are pretty heavy https://forums.radioreference.com/amateur-radio-general-discussion/263468-fcc-fines-ham.html

 

[prcguy]

Yup, most Icom, Kenwood, Yaesu and Flex can be modified but I've got some Elecraft and TenTec radios that will do everything but 26-28MHz.

Pretty well all the solid state rigs built since the 1980's can be modified. Some are easy, some are difficult. http://mods.dk has the and diagrams in a database. You need to sign up with them and they limit how much you can download. The more you 'donate' the more you can see.

Of course, you'd only be doing it as a matter of seeing whether or not it could be done and not actually transmitting out of band.. Right? (If you get caught, the fines are pretty heavy https://forums.radioreference.com/amateur-radio-general-discussion/263468-fcc-fines-ham.html

 

[wyShack]

Also remember the modification only allows the transmitter to turn on at those frequencies. The finial amplifier's output filter may or may not be designed to match to an antenna at the operating frequency. There may be a pole or zero in the filter that causes the finial to see a mismatch. The internal SWR meter and protection circuits are past the filter and will not 'see' the problem-resulting in a radio that is burns itself up. If using full power,you need to evaluate(and possibly modify) the output filter for satisfactory operation.

Evaluating the filter's impedance vs frequency is a little more involved than reading about and clipping a diode. If you get a low output power measured by an external meter, you know you have a problem but indicated full power could still 'blow' the finals.

This is one reason the specs are only guaranteed in the ham bands.

 

[swen_out_west]

Surprising this question on a mostly Ham Forum was not instantly flamed.

Disclaimer: Yes, it is illegal. You can buy some from dealers that will do the mod for you. Honestly, I have looked into this and have used friends radios that were modified, most were 10/12 meter rigs. You hear a lot of the Hams on 38LSB moonlighting as CB'rs (Which is in the thousands, btw) talking about their ICOMS and Yaesu's. Yaesu seems to be the most popular due to ease of mod. I settled on sticking with my little mud duck 980 ssb in the long run for CB.

As for the question, it's like asking what model car can break 110 mph (which in itself is now considered a felony in some places, but i'll bet most guys have actually done it at least once).. Most can with the right mods, some just can't. It's easier if you decide on the radio you want first and then before you buy it see if it can be modified and how difficult it may be (you might not be comfortable taking a soldering iron after a brand new radio trying to remove a 0 Ohm resistor that can only be seen with at least a 50x magnifying glass/microscope).

Youtube has thousands of videos that are brand/model specific. Sometimes listed as MARS Mod,

 

[BloodandRoses]

My Yaesu does just fine on transmit and receive on all of the bands including CB and freeband...

 

[prcguy]

While this might be true in theory, it doesn't seem to be a problem in actual use. I've seen hundreds of modified HF amateur radios and all the low pass filters switch at appropriate points and the radios seem to be designed for 1.8 to 30MHz continuous use from the factory. This covers radios made in the 70s through the latest models today. If there is a factory mod to broadband the transmitter, then the radio was designed that way and should function just fine anywhere within that range.

Also remember the modification only allows the transmitter to turn on at those frequencies. The finial amplifier's output filter may or may not be designed to match to an antenna at the operating frequency. There may be a pole or zero in the filter that causes the finial to see a mismatch. The internal SWR meter and protection circuits are past the filter and will not 'see' the problem-resulting in a radio that is burns itself up. If using full power,you need to evaluate(and possibly modify) the output filter for satisfactory operation.

Evaluating the filter's impedance vs frequency is a little more involved than reading about and clipping a diode. If you get a low output power measured by an external meter, you know you have a problem but indicated full power could still 'blow' the finals.

This is one reason the specs are only guaranteed in the ham bands.

 

[rbomba]

Check out Bells CB Radio. I'm sure you will find what you're looking for there.