From cbfsb!att!emory!ogicse!ucsd!news-mail-gateway Fri Jul 19 16:47:16 EDT 1991 Article: 5479 of rec.radio.amateur.misc Path: cbfsb!att!emory!ogicse!ucsd!news-mail-gateway From: kd6hr.El_Segundo@xerox.com Newsgroups: rec.radio.amateur.misc Subject: FT470 up dates Message-ID: <"19-Jul-91..7:45:02.PDT".*.PMcAfee.El_Segundo@Xerox.com> Date: 19 Jul 91 14:45:02 GMT Sender: daemon@ucsd.Edu Organization: UCSD Usenet Gateway Lines: 119 Thanks to Terry Wells for doing the fine job of documenting the Yaesu FT470 out of band mods. I might note that the information that Yaesu is sending out is from the Info-Hams posting of a few days ago. Pete McAfee kd6hr internet: kd6hr.el_segundo@xerox.com ================================================================== Until now, I had always followed the directions to the letter. But I decided it was time to analyze the side effect a little further. Here's what I found. Initial conditions for the side effect to occur: 1) Go to VFO. (VFO A or B will work, it doesn't matter.) (Press VFO) 2) Any frequency will work, In the initial example, 450.00Mhz was used. (Enter 50.00 from the keypad - radio goes to 450.00) 3) Set the repeater offset to 0.00MHz, but do not press any other buttons. (press F(M), press RPT, type 0000. Don't press anything else) 4) Turn the power off and on again. (Radio will return to VFO mode) (Twist left until the click, twist right past the click. Neat, huh.) This sets up the radio so that the side effect can exist. Once the side effect exists, you do not have to repeat steps 1 - 4 unless you change the repeater offset and want the side effect back again. To make use of the side effect, follow these steps: 1) Set transmit offset to + (- works too, but slightly differently, see section on low limit mod for details) (Press RPT twice) 2) Swap the transmit and receive frequencies. (Press REV) At this point, the computer gets confused since the transmit and receive frequencies are supposed to be the same (repeater offset = 0). The resulting side effect is that 1GHz is added to the current frequency. Pressing REV repeatedly alternately adds and subtracts 1GHz. Caveat: This is only true if one of the two frequencies (ex: 450.00 and 1450.00) is inside the currently available range of frequencies. If you have expanded the range of your receiver to 500Mhz, you may add 1GHz to achieve a new receive frequency of 1500MHz. You may not, however, continue leap frogging ad infinitum. The highest possible frequency is 1599.990 (with STEP(7) set at 10KHz). Leaping from 600.00MHz goes to 0.00MHz. This, in itself, is useful, as you may tune up from 0.00MHz and get any frequency down there that you want. Due to a loophole in the tuning software, you may tune from the current frequency towards the normal operating range (430.00 - 450.00), but not away. Once you tune down to a range in which the receive circuitry is sensitive (about 500MHz), you should store that frequency in the U memory. This now becomes the new upper frequency limit for the receiver (sort of). Unfortunately, you are still subject to the "tune one way only" syndrome. To bypass it, you must store some frequency in the L memory. It doesn't matter what this frequency is, but it has to be below the U memory and, preferably, below any other frequency you want to use. You may store a very low frequency here too (0.00MHz). BUT, the software isn't that dumb. To trick it, both the L and U memories must be filled and active (not set for SKIP), AND you must access the out of band frequencies from the MT (memory tune) mode, AND you must start from either the L or U memory. To use MT: 1) Press MR and select either the L or U memory. 2) Press MR again, a small MT should appear on the left of the display. 3) You may now tune with the arrow keys, Dial knob, or directly enter frequencies with the numeric keypad. The "NEW" lower limit side effect: Thanks goes to Pete McAfee, as he managed to run across yet another angle to this side effect. I have modified his procedure slightly as it isn't really necessary to key the transmitter. Pressing the REV key has the same effect. As you may recall (read the first part again if you forgot), setting the transmit offset to + and pressing REV alternately added and subtracted 1GHz from the current frequency. If you set the transmit offset to - and press REV, one of two things will happen. If you are above 1000MHz, the current frequency will drop by 400MHz (In Pete's example, 1450.00 dropped to 1050.00, and then to 650.00) Once you get below 1000MHz, the frequency will start shifting by 600MHz steps. If it is below the normal range (430.00 - 450.00), it will shift up. If it is above, it will shift down. Repeatedly pressing the REV key with RPT set to - yields these results: Frequency will swap between: 0.00MHz and 600.00MHz 100.00MHz and 700.00MHz 200.00MHz and 800.00MHz 300.00MHz and 900.00MHz Or any variation inside those limits. (250.00MHz <--> 850.00MHz) however, 400.00MHz --> 1000.00MHz --> 600.00MHz and we go back to case #1. Using this information you may tune to any frequency you wish. Unfortunately, the Rx hardware isn't sensitive very far outside its normal range. I currently have my UHF section set at 400.00MHz lower and 508.00MHz upper. It works great! -------------------------------------------------- Note!!!!!!! Be aware that this effect works on the 2 meter section as well. Since the 2 meter section is sensitive to a lower frequency range, you might want to experiment down there too.