First of all, the 4AT is one of the early synthesized portables. SWR shutdown wasn't real big back then. Also, I don't know of any ham radio that entirely shuts the TX down. Even a commercial Motorola MTR2000 won't do that. They cut the power way down, but don't shut the TX off. While I'm sure there is, somewhere, an SWR shutdown circuit that will do that, the 4AT certainly would not. Proof? Take the antenna off one. They still TX - the TX light still lights. For that matter, so does the HT1250, albeit a TX icon, not an LED.
I'm still betting on a flakey VFO. Joe M. Mike WA6ILQ wrote: > > Don't know how the radio is designed, but if there is a SWR- > sensing shutdown, it could happen. I've seen SWR sensors > that shut down the TX until the PTT was released. > > But if he is going to get inside the radio he can verify > the integrity of the antenna jack jumper in a few seconds. > > Lastly if anybody has a IC-2A or 2AT that is surplus to > their needs, operational and cheap let me know. The outer > case (including the touchtone pad) doesn't have to be pretty, > or even intact as I'm going to completely repackage it into > another housing. The speaker can even be dead. I just need > the HT electronics (including the mic cartridge) fully operational. > > Mike WA6ILQ > > At 08:04 PM 10/12/04, you wrote: > > >But would an intermittent antenna connector cause the TX light to go out as > >well? I'd guess not, but maybe. In any case, when it quits, the TX light > >also goes out. > > > >Chuck > > > > > > > >----- Original Message ----- > >From: "Mike WA6ILQ" <[EMAIL PROTECTED]> > >To: <[email protected]> > >Sent: Tuesday, October 12, 2004 9:54 PM > >Subject: Re: [Repeater-Builder] Off topic - HT repair > > > > > > > > > > At 06:17 PM 10/12/04, you wrote: > > > > > > > > >>Time to ask the guys who know... > > >> > > >>My old faithful Icom IC-4AT is experiencing intermittent TX. Sometimes the > > >>TX just cuts out, sometimes there's lots of crackling on the transmitted > > >>signal. This is an old HT - the one with thumbwheel frequency select. > > >>Looks > > >>like Icom wants $75/hr. repair rate. I can't believe the thing is worth > > >>$75. > > >> > > >>Can anyone suggest something more economical or is it time to say goodbye > > >>to > > >>my old and trusted friend? I just don't have the time, patience and > > >>eyesight > > >>to tackle an HT repair. > > >> > > >>Reply directly, please > > >>[EMAIL PROTECTED] > > >> > > >>Chuck > > >>WB2EDV > > > > > > Find someone with good eyes or one of those clamp-on-the-desk > > > work lights that has a 4" diameter magnifying glasses that is > > > mounted inside a circular florescent tube. > > > > > > Then closely inspect the connection between the center pin of > > > the BNC and the PC board. I'll bet you that it's broken and > > > making intermittent contact. Get in there with a fine soldering > > > tip and remove the broken jumper wire and excess solder then > > > make up a jumper using tiny braid - I use the really fine > > > solder-wick. I put a blob of solder in the BNC pin and on the > > > PC board and then QUICKLY tap the braid into each blob. > > > The intent is to have the solder-wick braid be a flexible > > > connection allowing the BNC center pin to move a little as > > > you insert and remove the antenna. > > > > > > Mike WA6ILQ > > > > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >Yahoo! Groups Links > > > > > > > > > > > Yahoo! Groups Links > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
