Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84 exptools; site ihu1h.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!ihnp4!ihu1h!parnass From: parnass@ihu1h.UUCP (Bob Parnass, AJ9S) Newsgroups: net.ham-radio Subject: Re: Modified PLL rigs Message-ID: <558@ihu1h.UUCP> Date: Wed, 1-May-85 15:55:24 EDT Article-I.D.: ihu1h.558 Posted: Wed May 1 15:55:24 1985 Date-Received: Thu, 2-May-85 02:41:25 EDT Distribution: net Organization: AT&T Bell Laboratories Lines: 39 x Out of Band Coverage for 2 Meter Portables > How easy would it be to modify the code in a modern PLL HT to enable tuning > out-of-band? It would be nice to have some additional receive range without > those kludgey band shifter antenna bolt-ons. I would think you can tell the > PLL to do whatever you want, you just have to get the software to believe > this. Changing the firmware in a 2m ht is not for the faint of heart. The older ICOM IC2's range may be extended to 140 - 150 MHz by cutting and soldering, no new components needed. 73 magazine detailed two ways to extend the coverage on the older Kenwood TR2400. One method used the injec- tion signal from the transmit PLL on receive, although the frequency display wouldn't track the true receive frequency. This resembles the old trick of placing the receive crystals into the transmit crystal sockets of older crystal controlled CB radios so they could transmit on 10 meters. Nowadays, 2 meter portables are used for non ham activities, particularly for warfare in the Middle East and Central America. Not wanting to miss a major market segment, Japanese manufacturers have started adding additional frequency coverage capabilities into their 2m rigs. The ICOM IC02AT's coverage can be modified by the addi- tion of a few diodes. The Kenwood TR2600A already cov- ers 140 - 160 MHz on receive right out of the box and can transmit the same wide range by cutting a two com- ponent leads. -- =============================================================================== Bob Parnass, Bell Telephone Laboratories - ihnp4!ihu1h!parnass - (312)979-5414