Well, I just read through the article at http://www.repeater-builder.com/rbtip/uhfsensitronRX.html and it says that this mod is not necessary if the freq being received is above 445 MHz... My RX freq is 449.550, but I cant get the current receiver sensitivity to tune any better than .6µV for 12dB SINAD.
I'm wondering if this mod will help even though the receiver is operating close to factory specs, or if I should just chuck this receiver board in the crapper in favor of a better one, or... Any ideas? Mark - N9WYS -----Original Message----- From: Repeater-Builder@yahoogroups.com On Behalf Of Bob M. Actually Dave, N1OFJ, who peruses this group, modified his receiver to go down to 444.475 MHz, following info he got from Kevin W3KKC. I suspect that info is on the repeater-builder site in the Motorola/Micor area, but if not, Kevin was the original source. It's the crystal multipliers that need padding, and not by much, perhaps 3-9pf. Bob M. ====== --- N9WYS <[EMAIL PROTECTED]> wrote: > Bob, > > Can you elaborate on where the "padding" needs to be > added? I'm using 2 UHF > (450) boards which have been tuned to 449... One > works just fine, but the > other needs some help. I know it's not all that far > out-of-range, but maybe > this one that is troublesome is being finicky. > > Also - Jordan, if you're looking to unload any of > those... I could use one > or two more. Contact me direct if this might be the > case. > > Mark - N9WYS > n9wys (<at>) ameritech (<dot>) net > > -----Original Message----- > From: Repeater-Builder@yahoogroups.com On Behalf Of > Bob M. > > Sorry, but while the chassis may be UHF, the > receiver > boards come in four flavors: 403-420, 450-470, > 470-494, 494-512. They're all wide-band (5 kHz). The > 450-470 MHz receivers can be coaxed down into the > 440 > MHz band by padding a few key spots. Look at the > part > number stamped on the receiver board. It should be > TRE120x, where "x" is 1, 3, 4, or 5 for the above > mentioned bands. While there's no "2" shown, it > would > be for 420-450, if they made a receiver for that > band. > > Bob M. > ======
