Hi again fellow Flexers! To continue the story below I lifted pins 9 and 8 on IC4C and connected pins 1 and 2 instead and re-connected pin 13 on IC 1 on the PIO board and pin 10 on IC 1 on the BPF board after finding I had TX/RX 5V on J5 pins 4 and 5 again - and thus I actually got T/R switching up and running again. Well, did this solve the dead (almost dead) reciever? Not exactly, but I got about 20dB closer to a live reciever by the look of it, but where are the missing still 70 or 80dB - burned INA?? It does get fed +/- 14.7V as measured on J5 so shouldn't it do the business?? I have TX, though only about 400mW in the -10dBV setting of my Delta 44, can squeeze out a full watt at the expense of some distortion when it's lifted to "consumer" level, indicating something is overdriven at this level, maybe the DRV 135's?? Is 400mW key down power common when running this unit from a 12V DC source? So where does all this lead? Well, some advice from someone who knows what he/she is talking about is most certainly still highly appreciated! It's somewhat frustrating at the moment, haven't been able to get hold of anyone who understands these digital circuits better than I do (which I am afraid leaves a lot to be desired). Another thing that bugs me is; What the heck caused this to happen in the first place? I sure would like find out, preferably not the hard way again! But first of all I would love to have this wonderful reciever back on-line, spuriouses, frequency drift, BC noise on 160M, warts and all, I truly miss its close in performance on a crowded European slice of the 80M band! Thanks in advance to any respondee, your help is as you can see just about invaluable ;-) OZ0FT, Frank
Had my unit (2003 vintage that I just acquired recently as a half finished project including the original case) temporarily set up with a 5V TX relay with an anti-transient diode across the coil connected to pin 7 and 8 on J5 to key a 20W amplifier relay and was running an initial check on my low pass filter board switching scheme also with 5V relays (2 per band). At a point during my experiments the 5V TX relay stayed keyed as the ground signal on pin 7 didn’t drop when I switched back to receive. The band switch relays were/are still operational. I lifted pin 10 on the ULN2003 (IC1 on the BPF board) to release K13, but no signals heard on the receiver. I then did the same with pin 13 on the 74AC5745 (IC1 on the PIO board) as I found it was in TX state with 5V out. This still didn’t solve the constant TX state problem. I suspect IC4C (PIO board) pins 9 and 8 is the culprit as the TX line is constantly on wherever I measure (checked the output to the TRX board on J5 pin 5 - yep, sure enough: 5V) Will lifting pin 9 do the trick, so I can carry on with the troubleshooting, I wonder. Or have I indeed sadly fried the whole setup here? I am not too keen on keeping de-soldering pins on IC’s as I dive deeper into the unit before someone with a bit more insight hopefully sees this and passes on some very much appreciated advice (don’t tell me to ditch the unit please, this rig has moved this hams expectations in radio to a whole new level, what a fantastic radio (Delta 44 here) – period) By the way, I hooked up my old Boonton signal generator and at 0dBm output from it, I measure a signal of -90 to -100dBm, depending on band, on the panadapter, so it seems the receive line is still alive even though it apparently isn’t being powered. Transmit worked before I de-soldered the above mentioned pins, a bit low on power though and with some strange noise on 160M that wasn’t present on the other bands. This was a bit of a long over, hope a fellow SDR 1000 aficionado out there can and will help out none the less. Vy 73 de OZ0FT, Frank. No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.20.7/1286 - Release Date: 18-02-2008 18:49 No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.20.8/1288 - Release Date: 19-02-2008 20:47 No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.20.9/1294 - Release Date: 22-02-2008 18:39 _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
