How long ago did you get them? There's been a lot of discussion here about RX performance variability, and the amount of testing they get has increased a lot in the last few months.
Cleaning off any flux residue from around the 2211 chip is an easy first thing to try. Scott Kent Hufford wrote: > > > I bought two OT2m's. I hooked one to a Yaesu FT-1900 in my shack and > watched it try and decode packets. It is having a hard time. > > > > I also have a PK-232 on a IC-229H running UI-View 32 and it is decoding > fine at the same time. > > > > I thought I just am having a "learning" experience with the OT2m. Is > there something I can do, or check to improve the decoding. We were > going to put this combo in the southern part of the county to give it > better Digi coverage. But not yet. > > > > thanks, > > Kent > > KQ4KK > > > > *From:* [email protected] [mailto:[email protected]] *On > Behalf Of *Mike Zwingl oe3mzc > *Sent:* Sunday, September 13, 2009 11:55 AM > *To:* [email protected] > *Subject:* Re: [tracker2] Tracker2/Display & poor decoding > > > > > > Scott, > > I guess you are talking abt C13 and C17 ? > > > > When you replace them, do you see improved decoding? > > > > sorry for the hassel. > > vy 73 de Mike > > oe3mzc > > > > > > ----- Original Message ----- > > *From:* Scott Miller <mailto:[email protected]> > > *To:* [email protected] <mailto:[email protected]> > > *Sent:* Sunday, September 13, 2009 4:42 AM > > *Subject:* Re: [tracker2] Tracker2/Display & poor decoding > > > > > > Hi Mike, > > I'm kind of fed up with the 2211 myself. I've been doing a lot more > testing on the OT2ms before they ship these days, and a significant > portion of them need to have the 0.027 uF capacitors replaced before > they ship. I'm not sure the batch sent to the contract manufacturer is > really meeting specs. > > I haven't run into any that didn't get up to par with the capacitor > replacement and a thorough cleaning of flux residue. Still, it's a lot > of hassle. I've got a few boards on the way to test a new MX614-based > layout. When those come in (sometime late in the week) I'll start doing > some side by side comparisons. Assuming I can get my crashed workbench > PC up and running again. I already bought a replacement, but I can't > run the software I need under Vista, and I can't get the machine to > load > XP Pro. > > Scott > > Mike Zwingl oe3mzc wrote: > > > > > > Hi, > > we have exactly the same problem and we are no newbies to packet > radio > > modems. > > The XR2211 decoder should perform much better, than it sometimes > does in > > OT2m. > > This modem chip is also used in some other tncs... > > but I did not change it for an TCM3105 or similar in the OT2m -so > far no > > time to test this... > > However we observe many OT2m units, that show POOR DECODE on > 1200baud on > > different radios and locations. > > Some only decode less than one third of all heard packets..we do not > > know why... > > However, we have also seen some OT2m units that do significantly > better > > than that, running same firmware. > > We are also aware of the wrong capacitor in the audio filter > circuit of > > some OT2m serial No. batches, but even if we soldered the correct C > > it is still showing very odd effects with poor decode and digipeater > > performance. > > We would be glad to have some solution offered, since OT2m is > starting > > to get widely used in our national APRS network as an intelligent > > digipeater > > or replacing old tncs, that could not do the NEWn-n paradigm. > > > > hw? > > vy 73 de Mike > > oe3mzc > > > > > > > > ----- Original Message ----- > > *From:* Mark Cheavens <mailto:[email protected] > <mailto:mcheavens%40usa.net>> > > *To:* [email protected] > <mailto:tracker2%40yahoogroups.com> <mailto:[email protected] > <mailto:tracker2%40yahoogroups.com>> > > *Sent:* Thursday, September 10, 2009 3:31 PM > > *Subject:* Re: [tracker2] Tracker2/Display & decoding > > > > > > > > With the modem chip used it is rare that a "weak" or "noisy" signal > > will get decoded. Is the audio "packet" 9600, 1200, or speaker audio? > > > > With 1200 baud packet you need to have de-emphasized (sp?) audio to > > the modem (TNC). Speaker audio DOES have de-emphasis, as should a > > "1200" baud port of the radio. > > > > (FYI- 9600 had NO pre- or de- emphasis) > > > > Just because you can HEAR a packet, does not mean the TNC can decode > > it. The signal to noise radio need to have a LOT of signal, and VERY > > little noise. > > > > Mark > > KC5EVE > > > > > > At 01:02 AM 9/10/2009, you wrote: > > > >> > >> > >> Hi there, > >> > >> I've Tracker2 connected to a Nuvi350 and was wondering why > >> sometime it > >> took a while before I could see some of the callsigns get into the > >> Favorite (after I did a delete all). So, I added an LCD display > to my > >> Tracker2 yesterday and found out that most of the time, Tracker2 > >> couldn't decode the packets (i.e. not displayed on the LCD) > >> especially > >> the weak ones. Now I'm wondering what else I need to do .. > Anyway, my > >> setup is .. Kenwood TMV71A/Data/BandB <-> Tracker2 with LCD <-> > Nuvi. > >> I brewed my own cable between the TMV71A and the Tracker2.. sending > >> packet out does not seem to be a problem. Is there anything in the > >> configuration that I need to do? > >> > >> TIA, > >> Mohd/9W2TPT > > > > > >
