Steve,

This very topic was part of the discussion this morning over the satellite XW-2A.

There are several items involved.

First - Although NO-84 PKT is currently APRSON, most of the time it is APOFF. If it is apoff, you will not get a reply.

Second - It is my belief the timing of the APRS Digi on the ISS is set too short. This would be the Response Time and TXDelay settings. Many of us report hearing what is probably the digi of our packet, but it does not display on our terminal. The packet is probably being "clipped" at the beginning preventing decode. The absence of a RED packet prompts a resend. There is no way of knowing if you doubled with another station or just did not decode your packet, so you just resend increasing the traffic on the Simplex frequency.

Third - Since a simplex frequency is being used, there are times when there is a lot of doubling on both the uplink and downlink directions.

Solution - For NO-84, give it a try again today and check the status on the web site. http://www1.findu.com/cgi-bin/pcsat.cgi

For ISS, try turning off the CAT (C-) just before sending near TCA, to see if that works.

BOB KO6TZ

I've been trying and trying to make APRS contacts through ISS (UHF) and NO-84 (VHF) for some time now and have been unsuccessful in all attempts even in cases where the bird was plenty high or right over my head. Here's my working conditions..

Icom IC-9100 using a microKeyer II (MKII) as the interface. SatPC32ISS, UISS (Pro Version), UZ7HO Soundmodem. The antenna array is a m2 Leo-Pack and the rotator is a Yaesu G5500 being controlled with a Green Heron AZ-EL unit. All software is the latest. Doppler shifting is working fine as SatPC32ISS, IC-9100, and GH controller are talking to each other without issues. I've listened to the outgoing sound of the packet and did not hear anything unusual. In almost every case I've tried the lowest power and increased power at varying levels without luck. I've monitored the outgoing audio and adjusted the TX on the MKII to varying levels to make sure the audio of the packet was not over cooked.

From what I can tell everything is working well together and I can see

incoming packets from other stations decoding on UISS and Soundmodem. However when I TX... No hits whatsoever. When I tested the system on the local APRS frequency it works fine and other stations are digipeating my packet signal.

I'm coming to the conclusion that this must be a problem with my settings in either Soundmodem or perhaps UISS. The packets going up never get repeated. On both birds I use CQ & Ariss (Tried others too) during the outgoing TX attempts but nothing. I would really like if someone who uses a similar setup and has things working to contact me.

I'm at wits end and now curtailing any further attempts until I get some information on what may be going on..

Steve Nordahl, NS3L Nazareth, Pa. NS3L(at)Yahoo(dot)com