“Don’t get cocky kid….”<\/p>\n
Just when everything seems to be going smoothly, Murphy arrives.\u00c2\u00a0 Two days before the WPX contest, it became clear the 80m softrock had developed an issue and was useless.\u00c2\u00a0 It lost half of the signal, and so was useless(on 5\/27) and required repairs.\u00c2\u00a0 Sideline that issue for now….<\/p>\n
The 40m skimmer session kept right on chugging.\u00c2\u00a0 A couple of problems became clear.<\/p>\n
All together, it looks like the skimmer posted about 8K spots while it was active during WPX.\u00c2\u00a0 Trying to figure out a way to check for errors.\u00c2\u00a0 Low priority – spot checking the spots showed most to be valid.<\/p>\n
The 80m SR problem was resolved on Monday evening.\u00c2\u00a0 After having made three passes over the op-amp section, I made a fourth pass, concentrating on components in the “ring” side of the op-amp output, as well as the path back to the QSD section.\u00c2\u00a0 Also made a first pass over the transformer solder joints, using a higher wattage iron.\u00c2\u00a0 80m issue resolved.\u00c2\u00a0 Odds are it was in the op-amp chain(seems to be the most common cause of the symptoms), but I suspect a cold solder on the transformer was the real culprit.<\/p>\n
Looking at the case from a dead home audio system as a permanent enclosure.\u00c2\u00a0 If I can fit everything in, it should be a good choice.\u00c2\u00a0 Time for a block diagram…<\/p>\n
<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
“Don’t get cocky kid….”<\/p>\n
Just when everything seems to be going smoothly, Murphy arrives.\u00c2 Two days before the WPX contest, it became clear the 80m softrock had developed an issue and was useless.\u00c2 It lost half of the signal, and so was useless(on 5\/27) and required repairs.\u00c2 Sideline that issue for now….<\/p>\n
The 40m skimmer session kept right on chugging.\u00c2 A couple of problems became clear.<\/p>\n
The softrock will need better band pass filtering if they remain active during operations, or switching to shut them down during transmit running CW skimmer at 192khz sample rate used a great deal of CPU time, averaged 45-50% CPU utilization. Limiting the number of decoders helped somewhat Reducing the scan rate to allow a 96Khz bandwidth drastically reduced the CPU usage.\u00c2 Running at 96khz required an average of 15-20% of the CPU, even with the limit on the number of decoders increased. The K9AY rx antenna worked well for the 40m SR skimmer.\u00c2 The problem is it will need to be split and amplified for 80m and 160m as well. <\/p>\n
All together, it looks like the skimmer posted about 8K spots while it was active during WPX.\u00c2 Trying to figure out a way to check for errors.\u00c2 Low priority – spot checking the spots showed most to be valid.<\/p>\n
The 80m SR problem was resolved on Monday evening.\u00c2 After having made three passes over the op-amp section, I made a fourth pass, concentrating on components in the “ring” side of the op-amp output, as […]<\/p>\n