Hi Skip, Sounds like you have expermented like i have been doing for sometime. The 780/880 radios work great in the 440 band however in the 430 not without moding them. The SM50 radios work great at the bigest site in Oregon and lets say the 1000ft tower is definatly loaded. The trick is to enclose them into a aluminum chassis with seperate cavitys for the transmit and the recieve. Yes for Repeater operation i would not recomend on a big site but for links and the power down to 10wt into the duplexer and a 24v fan kit they will last a very long time. DONOT use 12v fans mounted on the heat sink since it will vibrate the VCO & you wont like the outcome. Mount the fan on the box with a grill and make it neat like its factory made and everyone will be happy. I can send some pics if you want.
Mike -------------- Original message -------------- From: "skipp025" <[EMAIL PROTECTED]> VCO War Stories...? anyway... Until I replaced my vehicle Kenwood TK-880 & TK-780 radio stack last year with the current TK-8180 and TK-7180 radio... I ran my un-modified TK-880 into the 440-450 Amatuer Band. But not all the way... the receiver sens fell off some and the vco didn't like going down to 440.100 without re-adjustment. In cold weather it would go out of vco lock and beep at me until the car heater had some time to warm it up a bit. On a positive note the same radio also worked up on my 493 T-Band frequencies without mods. I was happy to leave things alone since my Amateur work is mostly with a portable radio. The potential problem with the SM-50 is the receiver front in is not so great for repeater operation. Links maybe but maybe not so great in modest to high power repeater operation on a busy mountain top. But I have yet to try one at a busy mountain top... I'm also using Midlands and they make great link radios... and they are more than dirt cheap on ebay. cheers, skipp > [EMAIL PROTECTED] wrote: > I am aware and have some that tune to the 420-470 band. And those radios are the TK-8180K2 radios. The other radios i am talking about are the TK-880K radios. You will need to modify the VCO if you want them to perform below 440mhz. I would prefer to use the Kenwood but the time it takes to modify and ge them to work there are a pain & i know them very well. The other hand you can get a small Motorola SM-50 and use the hacked software and they play very nice down to 430mhz and have for sometime. Nock on wood i have yet to replaced one in my link system and the audio and everything you want is on the 16pin connector. PTT,COR,TOR,GROUND,Muted & Unmuted Audio, Mic,13.8v etc. > > Mike > > -------------- Original message -------------- > From: "Jim B." <[EMAIL PROTECTED]> > Mike Mullarkey wrote: > > They will work but the Motorola SM-50 radio works much better and you don't > > have to modify the VCO. > > What Kenwood radios do you need to modify the VCO on to get them to work > on the ham bands? Every Kenwood commercial rig I've played with since > the 705/805 series has gone right into the adjacent ham band with > virtually no effort. I know the current vintage mobiles and hand-helds > are actually spec'd to cover either 2M or 420-450 with no mods at all! > > -- > Jim Barbour > WD8CHL >
