Re: LPF-Control PCB TX Logic at U3 & U7
¿ªÔÆÌåÓýNo problem¡ Jerry just confirmed it¡¯s a software bug that got in between version 50.0 and 66.9.?? I¡¯ll let the software gurus figger out where the bug is.? There are plenty of ya here in the forum monkeying with the code.?? Those of you that took parts out of your radios¡. PUT THEM BACK! ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of jjpurdum via groups.io
Sent: Saturday, March 22, 2025 3:56 PM To: [email protected] Subject: Re: [SoftwareControlledHamRadio] LPF-Control PCB TX Logic at U3 & U7 ? I can't help because my system's been down for over a month and I haven't been able to do anything with the software. ? Jack, W8TEE ? On Saturday, March 22, 2025 at 04:41:38 PM EDT, K9HZ <bill@...> wrote: ? ? Its not a hardware problem.? The radio has been working fine until recently when some software mods were made. ? Use some sound deductive reasoning here.? This problem did not exist a month ago with any transceivers that were build.? Then work was done on the software in a mad dash to close it out for the next version of the T41 book.? All of a sudden, there are issues with most/ everyone¡¯s radio.? What conclusion and action would you take from that?? Bobb some hardware out of you radio?... or go back and check out an earlier version of the software? ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of Rick Price via groups.io ? Oliver,? I was having some kind of feedback/oscillation problems a couple of weeks ago and traced it back to the T/R switch also.? The relays and associated parts all checked out but, when I removed the 3-"0" ohm resistors that were there in place of?the Low Pass Filter (160M) and inserted the parts for the LPF the problem stopped.? I wanted to go back and remove the filter parts and place just two "0" ohm parts at c14-c16 and a single cap at c-15 but never did.? Wondering if the oscillation problem boards have the "0" ohm resistors and not the LPF filter in place.? Maybe, I will try it later just thought I would mention what I had, when you suggested a possible feedback issue. Rick, KN4AIE ? ? From: [email protected] <[email protected]> on behalf of Oliver KI3P via groups.io <oliver@...> ? The situation I think we might have is that both TX_BPF_SEL and RX_BPF_SEL are HIGH during SSB transmit. This lets a little bit of the transmitted signal leak through the TR switch back into the amplifier input through the BPF selection stage, like this: ? ? These two lines are controller by GPIO register bank A: ? ? This register is set by the function call ; the code there looks correct and unchanged. Scanning the code, it all appears to be correct. Some judiciously placed statements like this will confirm: Debug("Set LPF GPA state: "+String(LPF_GPA_state,DEC)); ? The fix that I implemented (major change to radio layout) to cure the short that caused the burning smell has created a display freeze issue, so I'm not able to test this myself right now. ? ? ? ? ?
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