I'm really stuck! No Xmit Pwr. #ubitx
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HEEELLLPPP
I assembled a Ver.3 board and everything went very well but when I measured the power out it was dead. I don't have the best power meter. I was using MFJ tuner/watt meter, set to 35 watt scale, and I was getting about a half a needle width reading. I finally found " A Diagnostic Guide for uBitx" Thank you for that document Ufi Auttorri. I measured all of the TX measurements listed in the document and every one was very close. I went back through and checked again everything seemed normal I set the bias, I had beefed up the heat sinks for the 510's a little and have a fan on them, heat sink is isolated from ground and still no transmit power. The heat sink will after a while get a little warm. I borrowed a friends QRP guys Voltmeter/ watt meter interface and measure 10 microwatts not milliwatts. It seems like something is not coupling the RF through. So I'm kinda stumped as to what to test next.? Please Help someone, I love this radio. 73 N5FJK Chip |
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I will see if I can come up with a?germanium diode.?
I do have a digital storage o'scope... trying . Pay day is a ways off and I am tapped out so no more orders to the parts place this week. but have a wealth of junk just will take a bit.? I appreciate everything that everyone is suggesting. Thank you Frustrated Ham N5FJK Chip? |
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This will be a jumbled Mess But bear with me. I did the best I could to make this understandable and have included the PDF document as an attachment that the measurement were listed from
As I have said before you will find my measurements very close to what they should be . Just for the fun of it I replaced the 2 IRF510 and made no difference in the out puts. Any clues or help would be greatly appreciated.? This is one of the boards That I'm afraid might have been shoved out the door to make room for Ver4 Farhan paid DHL shipping when I only paid for Indian Postal. I'm sure this is not the case though. But someone may have skipped the final Transmit check. The receive is very good? Someday soon Maybe a Little Transmit. I hope this makes sense to someone . TX, PTT
50-ohm
dummy load,
no
modulation
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Quad-1, Q20, 2N3904,
base, pin 1 2.31 VDC? My Reading 2.24 VDC
¡° 18 Q20-2 1.6 VDC ¡° Quad-1, Q20, 2N3904, my reading 1.6 VDC
emitter, pin 2
¡° 19 Q20-3 7.5 VDC ¡° Quad-1, Q20, 2N3904, My Reading 7.28 VDC
collector, pin 3
¡° 17 Q22-1 6.7 VDC ¡° Quad-1, Q22, 2N3904, mine 6.7
base, pin 1
¡° 18 Q22-2 6.1 VDC ¡° Quad-1, Q22, 2N3904, mine 5.57
emitter, pin 2
¡° 19 Q22-3 11.4 VDC ¡° Quad-1, Q22, 2N3904, mine 10.0
collector, pin 3
¡° 17 Quad-1, Q40, 2N3904,
base, pin 1 2.2 VDC , mine 2.24 ?
?
¡° 18 Q40-2 1.6 VDC ¡° Quad-1, Q40, 2N3904, mine 1.6 VDC
emitter, pin 2
¡° 19 Q40-3 7.3 VDC ¡° Quad-1, Q40, 2N3904,mine 7.28? VDC
collector, pin 3
¡° 17 Q42-1 6.7 VDC ¡° Quad-1, Q42, 2N3904,mine 6.64VDC
base, pin 1
¡° 18 Q42-2 5.9 VDC ¡° Quad-1, Q42, 2N3904,mine 5.92 VDC
emitter, pin 2
¡° 19 Q42-3 11.3 VDC ¡° Quad-1, Q42, 2N3904,mine 10.0VDC
collector, pin 3
¡° 20 Q6-1 2.0 VDC Fig-5, mine 2.0VDC
section D5
Quad-2, Q6, 2N3904, base,
pin 1
¡° 21 Q6-2 1.3 VDC ¡° Quad-2, Q6, 2N3904,mine 1.3VDC
emitter, pin 2
¡° 22 Q6-3 9.8 VDC ¡° Quad-2, Q6, 2N3904,mine 9.6VDC
collector, pin 3
¡° 23 Q90-1 3.3 mine 3.52VDC
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¡° 24 Q90-2 3.0 VDC ¡° Quad-4, Q90, 2N3904, mine 2.8VDC
emitter, pin 2
¡° 25 Q90-3 11.3 VDC ¡° Quad-4, Q90, 2N3904 mine 10.0VDC
collector, pin 3 ?
26 Q911-1 0.22 VDC, My Reading 0.39 VDC
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27 Quad-4, Q911, 2N3904,
emitter, pin 1¡°? Q911-2 0.75 VDC ¡°?My Reading 1.06 VDC
base, pin 2? 0.75 VDC? My Reading 1.06 VDC
¡° 28 Q911-3 10.9 VDC ¡° Quad-4, Q911, 2N3904, My Reading 11.52 VDC
collector, pin 3
¡° 29 Q912-1 0.22 VDC ¡° Quad-4, Q912, 2N3904,? My Reading .37 VDC
emitter, pin 1
¡° 30 Q912-2 0.75 VDC ¡° Quad-4, Q912, 2N3904, My Reading 1.05 VDC
base, pin 2
¡° 31 Q912-3 10.9 VDC ¡° Quad-4, Q912, 2N3904, My Reading 11.5 VDC
collector, pin 3
¡° 32 Q92-1 0.22 VDC Fig-5,My Reading 0.36 VDC
?
¡° 33 Q92-2 0.84 VDC ¡° Q92, 1/4 PA driver, My Reading 1.05 VDC
2N3904, base, pin 2
¡° 34 Q92-3 10.9 VDC ¡° Q92, 1/4 PA driver, My Reading 11.5 VDC
2N3904, collector, pin 3
¡° 35 Q93-1 0.22 VDC ¡° Q93, 1/4 PA driver, My Reading 0.35VDC
2N3904, emmiter, pin 1
¡° 36 Q93-2 0.84 VDC ¡° Q93, 1/4 PA driver, My Reading 1.04 VDC?
2N3904, base, pin 2
¡° 37 Q93-3 10.9 VDC ¡° Q93, 1/4 PA driver, My Reading 11.45 VDC
2N3904, collector, pin 3
¡° 38 Q96-1 0.22 VDC ¡° Q96, 1/4 PA driver,My Reading 0.35VDC
2N3904, emmiter, pin 1
¡° 39 Q96-2 0.88 VDC ¡° Q96, 1/4 PA driver, My Reading 1.04 VDC
2N3904, base, pin 2
¡° 40 Q96-3 10.9 VDC ¡° Q96, 1/4 PA driver, My Reading 11.43VDC
2N3904, collector, pin 3
¡° 41 Q97-1 0.22 VDC ¡° Q97, 1/4 PA driver, 2N3904, My Reading 3.54VDC
emmiter, pin 1
¡° 42 Q97-2 0.84 VDC ¡° Q97, 1/4 PA driver, 2N3904, My Reading 1.04 VDC
base, pin 2
¡° 43 Q97-3 10.9 VDC ¡° Q97, 1/4 PA driver, 2N3904, My Reading 11.45 VDC
collector, pin 3 TX, PTT
50-ohm
dummy load,
no
modulation
44 Q94-1 3.1 VDC Fig-5, My Reading 4.7 VDC
section F3
Q94, IRF510, 1/2 PA final,
gate, pin 1
45 Q94-2 11.3 VDC ¡° Q94, IRF510, 1/2 PA final, My Reading 11.9 VDC
drain, pin 2
46 Q94-3 0 VDC ¡° Q94, IRF510, 1/2 PA final, My Reading 0.00 VDC
source, pin 3
47 Q95-1 3.3 VDC ¡° Q95, IRF510, 1/2 PA final, My Reading 4.82 VDC
gate, pin 1
48 Q95-2 11.3 VDC ¡° Q95, IRF510, 1/2 PA final, My Reading 11.9VDC
drain, pin 2
49 Q95-3 0 VDC ¡° Q95, IRF510, 1/2 PA final, My Reading 0.00 VDC
source, pin 3
50 U2-1 4.2 VDC ¡° LM78L05ACZ bias? My Reading 5.02 VDC
regulator, out, pin 1
51 U2-2 0 VDC ¡° LM78L05ACZ bias My Reading 0.00 VDC
regulator, gnd, pin 2
52 U2-3 10.9 VDC ¡° LM78L05ACZ bias My Reading 11.64 VDC
regulator, in, pin 3
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Howard that would be great The Scope is a 70 Mhz and I? have a 10x probe. Its a cheap Hantek DSO5072p?
I will be available tomorrow until 5pm central standard My e-MAIL IS CLATHAM@...?DIRECT PHONE IS 405-742-5278 DURING DAYTIME. |
Latham, Chip