Re: ND6T AGC implementation for uBIT-X

Here it is

73 Kees K5BCQ

Ordering Instructions for the AGC and Click Mini Kits.doc

Re: TDA2822 mystery

Mike aka KC2WVB

For comparison sake I looked at both the uBitX and the BitX40 since I have both rigs. Interestingly, while the uBitX uses the 2822 IC the BitX40 does not. The 40 meter rig uses the lm386. However, they were not kind enough to place the lm386 in a socket unlike the 2822 found in the uBitX.

I am counting my lucky stars I have not had an issue with the 2822. I am a bit distressed by the 2822 managing to muck with the PA when it went on the fritz. On the other hand from some experience using the lm386 I remember it as being fairly forgiving. So, I can't help but wonder what the design parameter was that placed the 2822 in the uBitX?

Show quoted text

On Sat, May 26, 2018, 12:22 PM Mike aka KC2WVB <rb5363@...> wrote:

Nice problem solving. Too bad it had to happen.

On Sat, May 26, 2018, 11:17 AM w1eat via Groups.Io <w1eat=[email protected]> wrote:
Well, I got my uBITX working just fine for me and decided it was a keeper, so I ordered some TDA2822 spares on Ebay and they came a couple of days ago, maked with the dreaded "WX".? The part which came in the socket on my board was not marked "WX" and gave me no trouble, but I just couldn't help wondering if those spares were OK or not. So, I replaced the known good, problem free part with one of the spares.

No problems.? Every thing sounded fine and there was no loud pop or acrid magic smoke.? Great.? I'm ready for trouble.? Using my trusty chip puller I removed the "WX" part and put the known good, problem free, original IC back in the socket, facing the right way, all the legs in their correct holes, and turned on the power.

In 3 seconds or so there was a loud pop and acrid magic smoke escaped into the room.? Somehow, the "WX" part managed to teach the?known good, problem free part how to be a bad boy, or maybe it just booby-trapped the circuit somehow.

But there is more.? I tried to key the transmitter, which has nothing to do with the TDA2822 audio amp, and there was a single blip and then all quiet.? No TX voltage, but the RX voltage was fine.? Thankfully, I'm retired and I was able to spend many hours removing parts, testing and replacing them.? I traced out all the circuit I could and found one bad solder joint of my own doing.? I removed the IRF510 finals and the TX voltage returned, so something is sick in the PA.? I built an outboard LM380 audio amp and wired it in using the TDA2822 solder pads.? Nothing heard, so I removed all the old AF amp parts from the board and cut some traces to isolate ?the AF amp wiring.? Attaching the LM380 amp differently, the receiver came to life and the TX voltage returned.? I jumpered the TX driver output to the low pass filters and isolated the PA wiring, giving me 1.1 watts out.? FWIW, the output is about 1.1 from 160 thru 10m.

So, now I have a QRPp rig, some solder burns and an unproved theory that the current surge that popped the IC also fried or shorted a land on PA part of the board that I haven't found yet.? I also have a renewed appreciation for the LM380 because the audio is now much cleaner and CW sounds more "bell like".? If I can get the PA back into action I will be ahead of where i was when the magic smoke escaped.

Tom W1EAT

Re: ND6T AGC implementation for uBIT-X

#50410

开云体育

Hi Lee's could you please repost payment instructions for the kits as I can't find relevant post Thanks Graham?

Sent from my Samsung Galaxy smartphone.

Show quoted text

-------- Original message --------

From: Kees T <windy10605@...>

Date: 23/05/2018 23:56 (GMT+00:00)

To: [email protected]

Subject: Re: [BITX20] ND6T AGC implementation for uBIT-X

Gilles,

The total price for 2 kits sent to France is $18.30 ($4.30 for the 2 kits plus $14.00 postage)

73 Kees K5BCQ?

Re: ND6T AGC implementation for uBIT-X

Dave de WS1ETI

#50409

Also will commit to 1 of each kit! Thanks!

Re: TDA2822 mystery

#50408

It might be interesting if someone would work up a test jig for evaluating and stress-testing the

"WX" series of amplifier chips.? Could be revealing to see just what the failure mode really is.

Arv
_._

Show quoted text

On Sat, May 26, 2018 at 10:22 AM Mike aka KC2WVB <rb5363@...> wrote:

Nice problem solving. Too bad it had to happen.

On Sat, May 26, 2018, 11:17 AM w1eat via Groups.Io <w1eat=[email protected]> wrote:
Well, I got my uBITX working just fine for me and decided it was a keeper, so I ordered some TDA2822 spares on Ebay and they came a couple of days ago, maked with the dreaded "WX".? The part which came in the socket on my board was not marked "WX" and gave me no trouble, but I just couldn't help wondering if those spares were OK or not. So, I replaced the known good, problem free part with one of the spares.

No problems.? Every thing sounded fine and there was no loud pop or acrid magic smoke.? Great.? I'm ready for trouble.? Using my trusty chip puller I removed the "WX" part and put the known good, problem free, original IC back in the socket, facing the right way, all the legs in their correct holes, and turned on the power.

In 3 seconds or so there was a loud pop and acrid magic smoke escaped into the room.? Somehow, the "WX" part managed to teach the?known good, problem free part how to be a bad boy, or maybe it just booby-trapped the circuit somehow.

But there is more.? I tried to key the transmitter, which has nothing to do with the TDA2822 audio amp, and there was a single blip and then all quiet.? No TX voltage, but the RX voltage was fine.? Thankfully, I'm retired and I was able to spend many hours removing parts, testing and replacing them.? I traced out all the circuit I could and found one bad solder joint of my own doing.? I removed the IRF510 finals and the TX voltage returned, so something is sick in the PA.? I built an outboard LM380 audio amp and wired it in using the TDA2822 solder pads.? Nothing heard, so I removed all the old AF amp parts from the board and cut some traces to isolate ?the AF amp wiring.? Attaching the LM380 amp differently, the receiver came to life and the TX voltage returned.? I jumpered the TX driver output to the low pass filters and isolated the PA wiring, giving me 1.1 watts out.? FWIW, the output is about 1.1 from 160 thru 10m.

So, now I have a QRPp rig, some solder burns and an unproved theory that the current surge that popped the IC also fried or shorted a land on PA part of the board that I haven't found yet.? I also have a renewed appreciation for the LM380 because the audio is now much cleaner and CW sounds more "bell like".? If I can get the PA back into action I will be ahead of where i was when the magic smoke escaped.

Tom W1EAT

Re: TDA2822 mystery

Mike aka KC2WVB

#50407

Nice problem solving. Too bad it had to happen.

Show quoted text

On Sat, May 26, 2018, 11:17 AM w1eat via Groups.Io <w1eat=[email protected]> wrote:

Well, I got my uBITX working just fine for me and decided it was a keeper, so I ordered some TDA2822 spares on Ebay and they came a couple of days ago, maked with the dreaded "WX".? The part which came in the socket on my board was not marked "WX" and gave me no trouble, but I just couldn't help wondering if those spares were OK or not. So, I replaced the known good, problem free part with one of the spares.

No problems.? Every thing sounded fine and there was no loud pop or acrid magic smoke.? Great.? I'm ready for trouble.? Using my trusty chip puller I removed the "WX" part and put the known good, problem free, original IC back in the socket, facing the right way, all the legs in their correct holes, and turned on the power.

In 3 seconds or so there was a loud pop and acrid magic smoke escaped into the room.? Somehow, the "WX" part managed to teach the?known good, problem free part how to be a bad boy, or maybe it just booby-trapped the circuit somehow.

But there is more.? I tried to key the transmitter, which has nothing to do with the TDA2822 audio amp, and there was a single blip and then all quiet.? No TX voltage, but the RX voltage was fine.? Thankfully, I'm retired and I was able to spend many hours removing parts, testing and replacing them.? I traced out all the circuit I could and found one bad solder joint of my own doing.? I removed the IRF510 finals and the TX voltage returned, so something is sick in the PA.? I built an outboard LM380 audio amp and wired it in using the TDA2822 solder pads.? Nothing heard, so I removed all the old AF amp parts from the board and cut some traces to isolate ?the AF amp wiring.? Attaching the LM380 amp differently, the receiver came to life and the TX voltage returned.? I jumpered the TX driver output to the low pass filters and isolated the PA wiring, giving me 1.1 watts out.? FWIW, the output is about 1.1 from 160 thru 10m.

So, now I have a QRPp rig, some solder burns and an unproved theory that the current surge that popped the IC also fried or shorted a land on PA part of the board that I haven't found yet.? I also have a renewed appreciation for the LM380 because the audio is now much cleaner and CW sounds more "bell like".? If I can get the PA back into action I will be ahead of where i was when the magic smoke escaped.

Tom W1EAT

Re: audio dropping out

#50406

Hi Dave,

Thats it uBitx.. this group deals with Bitx20/40/u with different circuits!

Raj

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At 26/05/2018, you wrote:
Raj,

I am not sure what you mean by avatar. It is the uBITX...is that what you are looking for?

Dave

Re: TDA2822 mystery

#50405

provided

1. you don't plug a mono head/earphone plug? and

2. try working at lower volume levels, even WX make should try to work

?Safest appears to introduce 7806 for the TDA chip alone. You can ssee that mod on this very site..

?Wish you best from ubitx

Regards
MVS Sarma
?

Show quoted text

On Sat, May 26, 2018 at 8:47 PM, w1eat via Groups.Io <w1eat@...> wrote:

Well, I got my uBITX working just fine for me and decided it was a keeper, so I ordered some TDA2822 spares on Ebay and they came a couple of days ago, maked with the dreaded "WX".? The part which came in the socket on my board was not marked "WX" and gave me no trouble, but I just couldn't help wondering if those spares were OK or not. So, I replaced the known good, problem free part with one of the spares.

No problems.? Every thing sounded fine and there was no loud pop or acrid magic smoke.? Great.? I'm ready for trouble.? Using my trusty chip puller I removed the "WX" part and put the known good, problem free, original IC back in the socket, facing the right way, all the legs in their correct holes, and turned on the power.

In 3 seconds or so there was a loud pop and acrid magic smoke escaped into the room.? Somehow, the "WX" part managed to teach the?known good, problem free part how to be a bad boy, or maybe it just booby-trapped the circuit somehow.

But there is more.? I tried to key the transmitter, which has nothing to do with the TDA2822 audio amp, and there was a single blip and then all quiet.? No TX voltage, but the RX voltage was fine.? Thankfully, I'm retired and I was able to spend many hours removing parts, testing and replacing them.? I traced out all the circuit I could and found one bad solder joint of my own doing.? I removed the IRF510 finals and the TX voltage returned, so something is sick in the PA.? I built an outboard LM380 audio amp and wired it in using the TDA2822 solder pads.? Nothing heard, so I removed all the old AF amp parts from the board and cut some traces to isolate ?the AF amp wiring.? Attaching the LM380 amp differently, the receiver came to life and the TX voltage returned.? I jumpered the TX driver output to the low pass filters and isolated the PA wiring, giving me 1.1 watts out.? FWIW, the output is about 1.1 from 160 thru 10m.

So, now I have a QRPp rig, some solder burns and an unproved theory that the current surge that popped the IC also fried or shorted a land on PA part of the board that I haven't found yet.? I also have a renewed appreciation for the LM380 because the audio is now much cleaner and CW sounds more "bell like".? If I can get the PA back into action I will be ahead of where i was when the magic smoke escaped.

Tom W1EAT

Volume pot question

brad martin

#50404

I see that the ubitx uses a 10k pot for the volume but I can’t seem to find a good knob for it. I do however have a 4.7k pot with a switch that has a more standard shaft size. Would I experience any ill effects by swapping the 10k for a 4.7k?

Brad

Re: audio dropping out

[email protected]

#50403

Raj,

I am not sure what you mean by avatar. It is the uBITX...is that what you are looking for?

Dave

Re: BITX QSO Afternoon/Evening, Sunday, May 27, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

[email protected]

#50402

I am still working on my mic. I don't get enough umph from it. I'll try a voice cq. Should we agree on a freq for cw qso's? 7030 khz works for me. I'm aware I can do cw anywhere my license allows. Thoughts?

Dave WS1ETI

TDA2822 mystery

#50401

Well, I got my uBITX working just fine for me and decided it was a keeper, so I ordered some TDA2822 spares on Ebay and they came a couple of days ago, maked with the dreaded "WX". ?The part which came in the socket on my board was not marked "WX" and gave me no trouble, but I just couldn't help wondering if those spares were OK or not. So, I replaced the known good, problem free part with one of the spares.

No problems. ?Every thing sounded fine and there was no loud pop or acrid magic smoke. ?Great. ?I'm ready for trouble. ?Using my trusty chip puller I removed the "WX" part and put the known good, problem free, original IC back in the socket, facing the right way, all the legs in their correct holes, and turned on the power.

In 3 seconds or so there was a loud pop and acrid magic smoke escaped into the room. ?Somehow, the "WX" part managed to teach the?known good, problem free part how to be a bad boy, or maybe it just booby-trapped the circuit somehow.

But there is more. ?I tried to key the transmitter, which has nothing to do with the TDA2822 audio amp, and there was a single blip and then all quiet. ?No TX voltage, but the RX voltage was fine. ?Thankfully, I'm retired and I was able to spend many hours removing parts, testing and replacing them. ?I traced out all the circuit I could and found one bad solder joint of my own doing. ?I removed the IRF510 finals and the TX voltage returned, so something is sick in the PA. ?I built an outboard LM380 audio amp and wired it in using the TDA2822 solder pads. ?Nothing heard, so I removed all the old AF amp parts from the board and cut some traces to isolate ?the AF amp wiring. ?Attaching the LM380 amp differently, the receiver came to life and the TX voltage returned. ?I jumpered the TX driver output to the low pass filters and isolated the PA wiring, giving me 1.1 watts out. ?FWIW, the output is about 1.1 from 160 thru 10m.

So, now I have a QRPp rig, some solder burns and an unproved theory that the current surge that popped the IC also fried or shorted a land on PA part of the board that I haven't found yet. ?I also have a renewed appreciation for the LM380 because the audio is now much cleaner and CW sounds more "bell like". ?If I can get the PA back into action I will be ahead of where i was when the magic smoke escaped.

Tom W1EAT

Re: RF power chain mods and improvements..

Jack Purdum

#50400

Just roto-tilled the garden yesterday...feels like someone spent all night over my shoulders with a jackhammer. Getting old's a bitch, but it still beats the alternative.

Jack, W8TEE

On Saturday, May 26, 2018, 10:18:12 AM EDT, ajparent1/KB1GMX <kb1gmx@...> wrote:

Soon as the order of MPSH10s show up I will be trying them.

In the mean time when pain subsides from putting up the vegetable garden
I have BF106s to try for Q90.? and maybe also the pre-driver.

Allison

Re: Re[Bitx20] Spare Raduino Boards and PCBs

#50399

开云体育

My guess would be $18 postage plus or minus $5?

Bill Maxwell on Tasmania has ordered several times.

He is way out in the "Boonies", takes about a month to get to him.

Here is some documentation.

TNX Mike

On 5/26/2018 2:34 AM, marjannorm wrote:

Hi Mike,
is your complete replacement raduino with nano programmed - either same as original or "improved" ?
also, can you give me a guesstimate for postage to Australia?
thanks and kind regards
Norm. Vk5gi
28/170 Main Road
McLaren Vale. ? SA. ? 5171
Australia

-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

RaduinoUMax1SCHP1.pdf

RaduinoUMax1SCHP2.pdf

Re: 2 meter bitx possible?

#50398

I'm also really curious about an inexpensive VHF/UHF MMIC. Searching around "BGA" takes me to NXP which has a wide selection of parts, but?no hits for?BGA591

-David

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On Fri, May 25, 2018 at 3:34 PM Jerry Gaffke via Groups.Io <jgaffke=[email protected]> wrote:

No hits for BGA591, can you give a link?

In some other forum, I recall a conversation between Ashhar and Allison regarding low noise mmic's for a VHF receiver front end.
Can't find it anymore.? Allison had a favorite, quite cheap, extremely low noise figure.
What was that part?

Jerry

On Fri, May 25, 2018 at 11:36 am, Ashhar Farhan wrote:

As an architecture, the ubitx is quite suitable upto 432 MHz. The changes needed would be as follows:

?

1. The front-end mixer would have to be an ADE-1 or and SBL-1. The current tranformers and BAT54s would cut it.

2. We will need a good band pass filter. Above 146 Mhz, stripline/coax filters are more likely candidates.

3. The LNA and power chain will need MMICs. they are cheap and easily ordered from . A pair of BGA591 can easily provide the obligatory 5 watts.

?

- f

--
David K4DBZ
Unofficial bitx chatroom:?https://discord.gg/CrHvWFc

Re: RF power chain mods and improvements..

#50397

Soon as the order of MPSH10s show up I will be trying them.

In the mean time when pain subsides from putting up the vegetable garden
I have BF106s to try for Q90.? and maybe also the pre-driver.

Allison

Re: ND6T AGC implementation for uBIT-X

#50396

Bill,

Yes, it will.

73 Kees K5BCQ

Re: Raduino CAD Files

#50395

Joe
I loaded Roger Clarks bootloader on one of the pills and it is working OK just on usb. A little off topic but I ordered one of the 400 encoders that I think is like the one you got, by the picture anyway. It's ?on a slow ?boat now so be a while before ?it arrives.?
--
Allen ?Merrell

BITX40 CW Carrier Mod - CW Waveform shaping ? #bitx40

#50394

I am curious if anyone has looked at the shape of the CW waveform generated by the BITX40 using the CW Carrier Mod associated with PE1NWLs Bitx40 sketch ?
It seems to me that there might be room for some improvement by modifying this to provide some simple waveform shaping via an R/C network.?
According to what I have read the rise and fall times for the CW envelope should be something in the order of 5mS or greater for good sounding CW, free of clicks.?
The output from the Raduino via D6 through the 4K7 resistor is essentially a square wave.?

I had a friend record my BITX40 CW signal and send the wav file back to me and I don't actually hear anything that sounds like key clicks, but the keying does sound a?
bit hard.?

Using an online R/C time constant calculator, I calculated that adding approximately 1 uF of capacitance to ground in this circuit (assuming a 4k7 series resistor) would
give the desired 5mS rise time on the?leading edge of the waveform, but I am not sure how to handle the trailing edge ? (I am software guy not an engineer).
Also would adding this additional capacitance to ground have any negative impact on the balanced modulator circuit ??

?Any suggestions ??

While pondering this I had another related thought. ?While keying the BITX40 with the carrier mod the mic amplifier is still active. Does this imply that we should?
be unplugging our microphones while operating CW on the BITX40 to avoid picking up any stray noise ????

Cheers

Michael VE3WMB?

Re: audio dropping out

#50393

I have an idea but which board avatar is this?

Raj

Show quoted text

At 26/05/2018, you wrote:
Ok, thanks all. I checked the pins on the connector. I also got rid of excess wiringing and resoldered the yellow orange and green wires to the audio jack. None of that helps. What I did find by listening to it for awhile is that the audio always dropped out when there where a lot of strong stations on or nearby in freq. I think this is a case of of the processor getting swamped due to lack of AGC. The audio always comes back after a bit, even if I just leave it alone! Thoughts?