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Re: Help! I think I may have just ruined my 9 year old's Chanukah
Gordon Gibby
¿ªÔÆÌåÓýHi friend, look, when I was 14 years old and building my first rig all by myself with zero significant previous experience (except for soldering together a shortwave receiver) --- I didn't know much EITHER.? ? You can't get upset with those of us who are
now 45 years down the road, and have fought through a zillion little problems to learn what we learned --- you just have to do the work to learn whatever it is that you need to learn to solve YOUR problem.
Thats exactly what all the rest of us had to do also....
and along the way you begin to have better test equipment, and you find nearby Elmers who may or may NOT be able to help you --- and you begin to understand the radiocircuits better and better and that makes you faster and faster....
there are DUES to pay in any human endeavor.
In every problem, you try and break it down into sections, the same way you eat an elephant one bite at a time....
You check to see if ground is actually at ground potential with power applied You check to see if +12 is really at +12 when whatever is turned on. You try the relays --- measure voltages when you actuate them by shorting the PTT and see if they click, if contacts go from open to closed (pick something that would have a different voltage on it in RX or TX, and see if it actually changed You try and see if you can find ANY stage that works --- if you put your finger on the volume potentiometer (to inject 60 cycle hum) --- do you hear hum in the speaker?? ?Is there any power to the speaker amplifier chip?
You work at it a little bit at a time, and when you get tired you come back later when you're fresh. Some times it helps tremendously to have a second system to compare to.? ?I don't remember if you are doing a ubitx or a bitx40, but they are very similar and you could get a bitx40 inexpensively to compare to and/or learn from.
In one email no one can teach you 40 years of experience but I can tell you that the more you try, the more you will learn.? ?I have struggled for more than 12 hours on many a problem, only to figure out a way to diagnose it in my sleep --- many a rig has
been repaired after I finally figured out the trick.....once it was that someone had literally put the WRONG TUBE in a Heathkit; another time I didn't realize what was the CORRECT tube --- a relative has fixed many an ICOM solid state rig by patiently working
on them with a service manual.
? You'll learn.? ? It doesn't come free of charge.
Cheers! gordon
From: [email protected] <[email protected]> on behalf of tausciam@... <tausciam@...>
Sent: Sunday, December 17, 2017 8:28 PM To: [email protected] Subject: Re: [BITX20] Help! I think I may have just ruined my 9 year old's Chanukah ?
On Sun, Dec 17, 2017 at 05:12 pm, Gordon Gibby wrote:
Somebody suggested I tune up to 7300 and see if I find a carrier on my HFrig at about 5.1...I didn't....the NIST broadcast is at 5.0...didn't find a carrier over it either. I'm sure it's easy for you... you had something to start with... a broken radio is not a starting point without the technical skills to fix it. I don't know anything about this radio. All I know is that when I put it in the box, I got .01 amps on idle, .02 when I pressed PTT. Yelling into the mic didn't change that. Adjusting RV1 and RV136 didn't change that. My dummy load registered no voltage at all.? I stretched out a dipole along the floor and connected it. Went from one end of the band to the other. No change in that low hiss at any point. Someone here told me to measure the voltage on the IRF510s legs directly. I did that and blew my final. It lights up....I can control volume. When I turn the tuning knob, the display acts like I'm tuning.... when I click PTT I hear a pop in the speaker and it goes dead while I talk. That's it. That's all it does.
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