WA Radio Scanner Users' Group

hi all.
does any body know how long you can transmitt on a mobile bc radio?
can they transmitt for long periods say 5 mins?

Wouldn't have thought it would be good for it to transfer that long, I know with our SES radios it'll stop transmitting after 30-45 seconds.

hmm, yes, you would think that the uniden radios would state it in the manual or it would have a cut off, i do know that once out of using my handheld 5w, it cut out once during a long transmition. out of seven years

What is it that you actually want to know? What is the legal length of a long transmission on a public cb channel, or is it an equipment question (programming commercial radios gives you the option of the tx timing out after a selected amount of time or not at all - for example the tv and radio stations who use two ways to transmit IFB to outside broadcasts often transmit for hours at a time on (private) UHF frequencies..).

I guess each manufacturer of public cb units can choose a tx time out or not....

on my handheld uniden uh052xr, ive been able to transmitt at 5w for about 5 mins.

i gues i wanted to know both?

Most mobile/base UHF CBs have no heatsink and I wouldn't risk transmitting for more than a few minutes to keep from excessively heating and damaging the final output (PA) transistors. Most radios have thermistors which will wind back the output power to protect the PA, but the circuit isn't always quick enough

Commercial rated transceivers like the Icom IC-400PRO, Philips FM-92 etc could transmit at 5W for much longer - even indefinitely.

vk6hgr wrote:Most mobile/base UHF CBs have no heatsink and I wouldn't risk transmitting for more than a few minutes to keep from excessively heating and damaging the final output (PA) transistors.

Commercial rated transceivers like the Icom IC-400PRO, Philips FM-92 etc could transmit at 5W for much longer - even indefinitely.

transistoids(those big transistors) or transisters?

slipknot wrote:hi all.
does any body know how long you can transmitt on a mobile bc radio?
can they transmitt for long periods say 5 mins?

It all depends how long the timeout on the radio lasts for. Some radios have timeouts like the tait i think its a minute 10 seconds or something. Where as a Uniden 088 will drop a continuous carryer. All depends on the 'timeout' on the radio. After you have transmitted for the ammount of time that the radios timeout goes for your transmition will be cut off and you'll have to key up again.

PRC-495 wrote: It all depends how long the timeout on the radio lasts for. Some radios have timeouts like the tait i think its a minute 10 seconds or something.

For the Tait, the timeout time depends completely on the programming.