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Hello Neil,

a. The transmit level of the pk900 is messed up.? It's too low, and the calibration procedure in the manual doesn't work.

What radio are you using here?? This is sometimes the the radio's fault as some radios require a lot more drive than TNCs are able to provide.? Some radios have a user configurable INPUT gain setting but can only be set via a Windows program (Kenwood v71).? Your radio also might have different audio input paths (direct input, pre/post-emphasis, etc) so try that.? The last idea could be to create a small amplification stage to help increase the level.? There are lots of ideas on the repeater-builder.com site.

b. The pk900 was able to easily decode packets from direwolf even if it couldn't respond.

3. linpac+direwolf+radio over the air to radio+mfj-1274+linpac

a. This appeared to work as well as direwolf for my tests.

b. Eventually this tnc stopped working like the other 30+ year old tnc that I could find.

Was it the pk900 or the MFJ1274 TNC that failed?

And then there is stuff that still doesn't work.? I cannot connect to some of the local digipeaters even though the operators of those stations have assured me that they accept connections. I'm going to have a chance to meet some of them in person soon. I'll get to the bottom of this.

Are you trying every different possible SSID when trying to create a connected session?? It's tedious and takes time but it's the only way to really know.?

Maybe I have badly estimated what 5W can deliver on packet radio.

I would say your first priority should be what kind of antenna you're using (ideally a quality gain antenna), how high up is it located, minimize RF loss through the transmission line (use the shortest length of low loss coax).? After that, 5 watts can work but it's not ideal.? If possible, try to run at least 20-25 watts to create full quieting signals to override any on-frequency noise, override other distant hidden packet nodes, etc.

Maybe the old tnc hardware needs a very strong signal to decode direwolf.

Absolutely.. they need both good, strong signals but they also usually MUST have the proper signal levels on the two tones.? Legacy TNC like the MFJ units do NOT deal well with incorrectly pre-emphsized signals caled "twist".? Read up on that here:

??

?? /g/direwolf/topic/alsaloop_for_multimode/86155161?p=,,,20,0,0,0::recentpostdate/sticky,,,20,0,0,86155161,previd=1634510875111696413,nextid=1632149908223699678&previd=1634510875111696413&nextid=1632149908223699678

?

But I can play with packet radio just through my own nearby stations for now.? There are some new features(at least new compared to 1992 when I last used packet radio) that I can test.

In addition of the great decode performance, check out FX.25 which can dramatically improve the reliability of 300bps HF packet.

I appreciate the outpouring of help.? Now I'm going to go bug the guys at the linpac sourceforge site over a few issues.? Regardless of what help they might offer they're not going to be as cool of a bunch as you guys on the direwolf forum(unless of course they also frequent the direwolf forum).

Ha.. that would be me and I saw your post about YACC file transfers.? I need to reply there but there is some known issues there on YACC.? If I remember correctly, the AutoBin approach works ok.

--David
KI6ZHD