[Drakelist] T-4XB - R-4B injection anomoly
B-Liners, Looking for advice on how to pursue fixing a new issue with my B-Line. I wasn't even sure how to name or categorize it. I will post a recording of the sound of the problem which may help in analysis. It's a problem that suddenly appeared without me making any changes, so I initially trued tube substitution with some success, but not continuing success. I replaced V9 and the rig seemed stable for quite a while. I exercised PTT with not problems, but after half-hour of idle time, I closed the PTT line, and when released, the problem had returned. All switches have been cleaned in the last year or so, and up until this started, things have worked well, with only the loss of sidetone on CW as an unresolved problem with this pair. I mention it, just in case it may be relevant. Prior to that, I used CW on this rig very infrequently, but have had several years of excellent performance. There are short videos at: https://picasaweb.google.com/kfourso2/BLineWoes?authkey=Gv1sRgCOrp6InRlOXENw This problem is in SSB only I have not attempted relay contact cleaning, but this seems like a component value drift, or capacitor leakage type issue. My hope is that someone has already experienced this problem, and solved it. Thanks for any analysis and suggestions... -- *73, Mark, K4SO *www.k4so.com picasaweb.google.com/kfourso picasaweb.google.com/kfourso2 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] T-4XB CW sidetone and related issues
Hello Drakelist, I can obtain a sidetone for a short period after I turn on the transmitter. It is somewhat raspy, then is gone. I have tried several 12AX7As in V9, and only one provides a sidetone, but only briefly. I did try a little freeze spray on components around that tube, but I wasn't very specific. The mic gain also seems somewhat low. VOX is tending to clip the first character, even with a fairly level of VOX gain., The anti-vox is most of the way up, to raise the sidetone, while it lasts. I have a sidetone in my keyer, and the CW from the transmitter itself sounds fine, but I'd like to restore full functionality. Any thoughts on likely culprits? Thanks in advance for your input. -- *73, Mark, K4SO *www.k4so.com picasaweb.google.com/kfourso picasaweb.google.com/kfourso2 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] For Sale: AC-4, suitable for AC-4R
Hello! AC-4, working, and in good condition, but probably a candidate for Heathkit shop AC-4R board. I just figure all of them are at this age. Good sheet metal, relay connector, but needs a replacement fuseholder. I cobbled one in there, but it's too deep for permanent use, but allowed me to test the unit on a variac. It also has a two prong AC cord, which is spliced on the end of the original 2 conductor AC cord. A 3-wire cord is recommended anyway. $50 plus shipping, conus. Questions! Just ask. Thanks for looking. -- *73, Mark, K4SO *www.k4so.com picasaweb.google.com/kfourso picasaweb.google.com/kfourso2 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] AC-4 Sold
Thanks all for your interest! I have a buyer and a backup. I wish I had a few of these. -- *73, Mark, K4SO *www.k4so.com picasaweb.google.com/kfourso picasaweb.google.com/kfourso2 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
