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Re: troubleshooting no TX SSB
#ubitx
#ubitx-help
I did have power on CW, at least the first day before so smoked U1 with a stereo Sony noise canceling headset.
I didn't have my straight key yet bit i just shorted a cord that i had plugged in the key jack. Had some trouble getting the scope to sync but the signal on the collector of Q6 was much stronger than the Mic input. Scope has 10MHz bandwidth so it should work on the lower bands. Most likely the TDA will arrive saturday than i can start from scratch again. Will measure the voltages as you mentioned. But as CW seemed to work the first day I thought I had to look somewhere in the modulating circuitry. Have the schematics printed but in my professional career I worked more with higher voltages. Am not afraid to try but just need some guidance as I am fairly new to radio electronics. John |
Re: U1 fried
So where did you get your spare TDA2822M's?
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The TDA2822M is $7 for two on ebay, quite expensive for what it is. Mainline distributors like Mouser and Digikey say it's discontinued. ST no longer makes it, sources may be drying up. My uBitx has a part on it marked "TDA2822M" but no ST logo, not sure who makes it. Banggood has this amp, photos show it to be stuffed with a UTC2822H clone, but I'm having no luck finding a source for that chip either. ?? Someday we might need to find a replacement. Maybe a little PC board with 8 header pins. Stuff it with a bunch of mmbt3904's if nothing else. Curious that the stereo headset fried the TDA2822M. Perhaps it presented too low an impedance when first plugged in for some reason?? Not at all clear from the datasheet that the TDA2822M will survive a 4 ohm speaker when powered from a 12v+ supply. Jerry, KE7ER On Wed, Feb 28, 2018 at 02:22 pm, John wrote:
I fried mine when I plugged in a stereo sony noise canceling headset. |
Re: Another shipping Notification Update
ordered my Ubitx Dec. 27, 2017 Rcv'd yesterday Feb.27, 2018. had to be here and sign for it re DHL 73 WA9DOH On Wed, Feb 28, 2018 at 7:13 AM, Daniel Conklin <danconklin2@...> wrote: I ordered mine on the 29th of December 2017, and I haven't gotten notice of shipping yet. |
Re: U1 fried
I fried mine when I plugged in a stereo sony noise canceling headset.
So it does not only happen with mono plugs. Hopefully the spare TDAs with sockets will arrive soon so Incan start troubleshooting my no power problem. To be on the safe side and avoid another wait I also ordered some IRFs ;) John |
Re: ubitx standoffs
#parts
On Wed, Feb 28, 2018 at 01:38 pm, Jerry Gaffke wrote:
ACE Hardware store has an amazingI was just there last Saturday to get some M3 screws.? I didn't even think to look for knobs!? I'll pay more attention next time, and maybe have some coffee before I go. |
Re: ubitx standoffs
#parts
For those in the US, bereft of a 3D printer, our local ACE Hardware store has an amazing
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collection of nuts and bolts and spacers, nylon and brass and steel, imperial and metric. Including some nice generic knobs for electronics.? ? Nylon spacers are easily cut to size with an Xacto knife. Jerry, KE7ER On Wed, Feb 28, 2018 at 12:10 pm, Michael Hagen wrote:
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Fw: [BITX20] Another shipping Notification Update
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-----Original Message-----
From: Richard Stanley Sent: Wednesday, February 28, 2018 4:56 PM To: [email protected] Subject: Re: [BITX20] Another shipping Notification Update My paypal still says nothing but just got a text message from DHL asking for ?27 Their website says delivery by end of business on Monday (y) Richard G7OED -----Original Message----- From: Vince Vielhaber Sent: Wednesday, February 28, 2018 4:20 PM To: [email protected] Subject: Re: [BITX20] Another shipping Notification Update Check paypal in case you just didn't get the notice. Vince. On 02/28/2018 08:13 AM, Daniel Conklin wrote: I ordered mine on the 29th of December 2017, and I haven't gotten notice-- Michigan VHF Corp. |
Re: ubitx standoffs
#parts
¿ªÔÆÌåÓýHere is my BitX.. 3D printed spacers, Knobs, and Bezel.?
It is like cheating to make exactly the spacer you need!? Since
they are ABS, I can heat a 4-40 bolt on the stove and TAP them
with treads too.?? The LCD Backlight has a bump at one end,? so
to get the LCD parallel you need an inside spacer about 1/8". Mike, WA6ISP
-- Mike Hagen, WA6ISP 10917 Bryant Street Yucaipa, Ca. 92399 (909) 918-0058 PayPal ID "MotDog@..." Mike@... |
Re: Ubitx case
#ubitx
¿ªÔÆÌåÓýThere is a news article about Carl's
case on uBITx.net, but you are right, it should be discussed in
the enclosures page.? I will update the page shortly.
73 Mike ZL1AXG On 1/03/18 4:17 AM, Neil Goldstein wrote: Should we add Carl's case to the ubitx.net enclosures section.
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Re: U1 fried
I'm glad that works for you.
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But when concocting a recommended solution across thousands of rigs, we'd best somehow make the rig survive an audio short to ground.? ? Or this forum will getting traffic about fried TDA2822M's for years to come. On Wed, Feb 28, 2018 at 10:55 am, Thomas Sharka wrote:
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Re: U1 fried
Re-read this post:??/g/BITX20/message/42723
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Adding a series 8 ohm 1/2 watt resistor between the uBitx board and your phone jack should? safely prevent any damage, though it will reduce the maximum available audio. Could be that 4 ohms is sufficient. ? Jerry On Wed, Feb 28, 2018 at 10:49 am, Walter wrote:
So what is the universal fix?? if a mono jack is plugged into a stereo jack on another electronic device it does not destroy the audio output of those devices. |
Re: U1 fried
I just wired the stereo jack as a mono jack. The signal goes to the tip and the ground goes to the sleeve. The ring isn't connected. Now when I plug in a pair of stereo headphones, I only get one channel, but if I plug in a mono jack, I get sound. When I swap plugs, the short never happens. ? Sent from Yahoo Mail. On Wednesday, February 28, 2018 1:49 PM, Walter <W9KJO@...> wrote: So what is the universal fix?? if a mono jack is plugged into a stereo jack on another electronic device it does not destroy the audio output of those devices. How do they prevent damage on many other devices with stereo jacks? -- 73, W9KJO Walter |
Re: ubitx standoffs
#parts
Mike, I left out the statement:? very clean lines and sweet looking in and out.? Good work.
Ron ? KJ4FFG |
Re: ubitx standoffs
#parts
Thank you very much for your comment Craig.
Mike, I intend to at least get the display mounted recessed back at a minimum of the thickness of the panel material.? Some good thoughts about what to use. Thanks all, Ron ? KJ4FFG |
Re: Completed radio and it is not working
OK so I got a new 7805, installed it and the rig is now working. The tuner is a little hinky but it works. I may look into a 10 turn pot down the road. The problem I have now is the audio is very low almos inaudible. I am hearing stations but very low volume. I have tried different speaker with no effect.
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Re: U1 fried
¿ªÔÆÌåÓýJerry, After re-reading your post I now see your point.? But I think it a lot less likely that someone would plug a mono plug into a mono to stereo adapter IMHO. Mike K5ESS ? From: [email protected] [mailto:[email protected]] On Behalf Of Jerry Gaffke via Groups.Io ? I assume the mono to serial adapter would just short the mono signal to both stereo signals. It appears at least a few folks have fried U1 by inserting a mono plug in the speaker jack and shorting out the audio.? I¡¯d recommend only wiring up the tip connection and not the ring and then using an external mono to serial adapter for your stereo phones. ? |