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Have the ver 4 ubitix board, and very low to no audio. I see it has no TD2822M chip, has that changed or was it not mounted?
Board #849.
John
KD0MOA
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V4 has no TD2822M as it was prone to fail (mine too)
Il 09/lug/2018 19:15, "John Malone" < jmalone0360@...> ha scritto: Have the ver 4 ubitix board, and very low to no audio. I see it has no TD2822M chip, has that changed or was it not mounted?
Board #849.
John
KD0MOA
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ubitx4's TDA2822 has been replaced by a discrete audio amplifier. The low audiio must be due to some other reason. It has reasonable audio level. - f
On Mon, Jul 9, 2018 at 10:45 PM, John Malone <jmalone0360@...> wrote: Have the ver 4 ubitix board, and very low to no audio. I see it has no TD2822M chip, has that changed or was it not mounted?
Board #849.
John
KD0MOA
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My v4 ubitx has low audio if I try to use a speaker, with headphones it is reasonable.
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I got around that by plugging the radio into a little "Honeytone" audio amplifier.
it's available in several colors. I have one in Burgundy. That link is to one in Aqua. It has great sound for its size. If you want to use headphones, you can plug them into the amplifier rather than unplugging from the rig.
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The volume increases a lot if you do the quiescent current adjust mod that I have
described before.
Cut track between D15 and D16.. solder a multiturn vertical preset between the
two diodes and zero the preset resistance and slowly increase the preset till
the volume of background noise stops increasing. Check if final audio transistors
are hot, if hot reduce the preset..
Raj
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At 10-07-18, you wrote: My v4 ubitx has low audio if I try to use a speaker, with headphones it is reasonable.
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Raj, that is a solution, but isn¡¯t it fairly simple just to use a low parts count LM 386 amplifier for all this? It seems to me that making such a widely available part work properly would be the better long-term solution, able to work with multiple output impedances, temperatures voltages etc.
Am I missing something?
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On Jul 10, 2018, at 02:01, Raj vu2zap <rajendrakumargg@...> wrote:
The volume increases a lot if you do the quiescent current adjust mod that I have
described before.
Cut track between D15 and D16.. solder a multiturn vertical preset between the
two diodes and zero the preset resistance and slowly increase the preset till
the volume of background noise stops increasing. Check if final audio transistors
are hot, if hot reduce the preset..
Raj
At 10-07-18, you wrote:
My v4 ubitx has low audio if I try to use a speaker, with headphones it is reasonable.
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Gordon,
The v4 audio works fine but a little low on gain. Farhan has inadvertently forgotten to add that extra component required.
The mod is extremely simple, anyone can do it. At low volumes you can distinctly hear the improvement and increase
in volume.
The change was made so that uBitx will not depend on chips that are obsolete or parts that may become..
I sincerely dislike the LM386!
Raj
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Show quoted text
At 10-07-18, you wrote: Raj, that is a solution, but isn?€?t it fairly simple just to use a low parts count LM 386 amplifier for all this? It seems to me that making such a widely available part work properly would be the better long-term solution, able to work with multiple output impedances, temperatures voltages etc. Am I missing something? > On Jul 10, 2018, at 02:01, Raj vu2zap <rajendrakumargg@...> wrote: > > The volume increases a lot if you do the quiescent current adjust mod that I have > described before. > > Cut track between D15 and D16.. solder a multiturn vertical preset between the > two diodes and zero the preset resistance and slowly increase the preset till > the volume of background noise stops increasing. Check if final audio transistors > are hot, if hot reduce the preset.. > > Raj > > At 10-07-18, you wrote: >> My v4 ubitx has low audio if I try to use a speaker, with headphones it is reasonable. > > > >
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raj,
is there any other way of increasing the quiescent current by just changing the value of components? that might be an easier mod. something that i can even ask the production to do.
- f
On Tue, Jul 10, 2018 at 11:31 AM, Raj vu2zap <rajendrakumargg@...> wrote: The volume increases a lot if you do the quiescent current adjust mod that I have
described before.
Cut track between D15 and D16.. solder a multiturn vertical preset between the
two diodes and zero the preset resistance and slowly increase the preset till
the volume of background noise stops increasing. Check if final audio transistors
are hot, if hot reduce the preset..
Raj
At 10-07-18, you wrote:
>My v4 ubitx has low audio if I try to use a speaker, with headphones it is reasonable.
|
The LM386 can be improved. Here are some great mods to the chip we love to hate
Gordon,
The v4 audio works fine but a little low on gain. Farhan has inadvertently forgotten to add that extra component required.
The mod is extremely simple, anyone can do it. At low volumes you can distinctly hear the improvement and increase
in volume.
The change was made so that uBitx will not depend on chips that are obsolete or parts that may become..
I sincerely dislike the LM386!
Raj
At 10-07-18, you wrote:
>Raj, that is a solution, but isn¡¯t it fairly simple just to use a low parts count LM 386 amplifier for all this?? ?It seems to me that making such a widely available part work properly would be the better long-term solution, able to work with multiple output impedances, temperatures voltages etc.? Am I missing something? > On Jul 10, 2018, at 02:01, Raj vu2zap <rajendrakumargg@...> wrote: > > The volume increases a lot if you do the quiescent current adjust mod that I have > described before. > > Cut track between D15 and D16.. solder a multiturn vertical preset between the > two diodes and zero the preset resistance and slowly increase the preset till > the volume of background noise stops increasing. Check if final audio transistors > are hot, if hot reduce the preset.. > > Raj > > At 10-07-18, you wrote: >> My v4 ubitx has low audio if I try to use a speaker, with headphones it is reasonable. > > > >
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I don¡¯t think you can go wrong by inserting a fixed value resistor between the diodes of something like 47 ohms¡ ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Ashhar Farhan
Sent: Tuesday, July 10, 2018 10:29 AM
To: [email protected]
Subject: Re: [BITX20] ubitix v4 ? raj, is there any other way of increasing the quiescent current by just changing the value of components? that might be an easier mod. something that i can even ask the production to do. ? On Tue, Jul 10, 2018 at 11:31 AM, Raj vu2zap <rajendrakumargg@...> wrote: The volume increases a lot if you do the quiescent current adjust mod that I have
described before.
Cut track between D15 and D16.. solder a multiturn vertical preset between the
two diodes and zero the preset resistance and slowly increase the preset till
the volume of background noise stops increasing. Check if final audio transistors
are hot, if hot reduce the preset..
Raj
At 10-07-18, you wrote:
>My v4 ubitx has low audio if I try to use a speaker, with headphones it is reasonable.
? -- ¡_. _._
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I am a little hard of hearing, due to a divorce.
I bought this amp?
12 bucks? and works great.? I have it at half volume on the amp pot.
Vern
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Farhan,
As the mad radio modder said put in a resistor and provide the through
holes for a trimmer if the
user wants to be able to fine tune it. 33-39 ohms is safe.
Raj
At 10-07-18, you wrote:
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Show quoted text
raj,
is there any other way of increasing the quiescent current by just
changing the value of components? that might be an easier mod. something
that i can even ask the production to do.
- f
On Tue, Jul 10, 2018 at 11:31 AM, Raj vu2zap
<
rajendrakumargg@...> wrote:
- The volume increases a lot if you do the quiescent current adjust mod
that I have
- described before.
- Cut track between D15 and D16.. solder a multiturn vertical preset
between the
- two diodes and zero the preset resistance and slowly increase the
preset till
- the volume of background noise stops increasing. Check if final audio
transistors
- are hot, if hot reduce the preset..
- Raj
- At 10-07-18, you wrote:
- >My v4 ubitx has low audio if I try to use a speaker, with
headphones it is reasonable.
|
Farhan,
What I would like to see uBitx become more hacker friendly. Please put
the audio on a daughter board
with a 0.1" pitch socket so we can plug in any chip or discrete home
brew board
Secondly daughter boards for the filter and the two bidi amps which I
call townships.
The mother board will shrink and be more hackable.
I guess that costs will come down a bit..
Raj
At 10-07-18, you wrote:
toggle quoted message
Show quoted text
The LM386 can be improved. Here
are some great mods to the chip we love to hate
On Tue, 10 Jul 2018, 16:45 Raj vu2zap,
<
rajendrakumargg@...> wrote:
- Gordon,
- The v4 audio works fine but a little low on gain. Farhan has
inadvertently forgotten to add that extra component required.
- The mod is extremely simple, anyone can do it. At low volumes you can
distinctly hear the improvement and increase
- in volume.
- The change was made so that uBitx will not depend on chips that are
obsolete or parts that may become..
- I sincerely dislike the LM386!
- Raj
|
Raj, the price will go up, not come down. It will also be another thing for newbies to be confused about. For those who want to use a different audio amp, you have to just wire it up out of the volume control. It is as easy ss it gets even now. - f
Farhan,
What I would like to see uBitx become more hacker friendly. Please put
the audio on a daughter board
with a 0.1" pitch socket so we can plug in any chip or discrete home
brew board
Secondly daughter boards for the filter and the two bidi amps which I
call townships.
The mother board will shrink and be more hackable.
I guess that costs will come down a bit..
Raj
At 10-07-18, you wrote:
The LM386 can be improved. Here
are some great mods to the chip we love to hate
On Tue, 10 Jul 2018, 16:45 Raj vu2zap,
<
rajendrakumargg@...> wrote:
- Gordon,
- The v4 audio works fine but a little low on gain. Farhan has
inadvertently forgotten to add that extra component required.
- The mod is extremely simple, anyone can do it. At low volumes you can
distinctly hear the improvement and increase
- in volume.
- The change was made so that uBitx will not depend on chips that are
obsolete or parts that may become..
- I sincerely dislike the LM386!
- Raj
|
I just soldered a third silicon diode between the original ones (the foil cut of course). No distortion anymore.
OH3WE Kai
|
The transistor must be running really hot!
Raj
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Show quoted text
At 03-02-19, you wrote: I just soldered a third silicon diode between the original ones (the foil cut of course). No distortion anymore.
OH3WE Kai
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Gwen Patton
Raj vu2zap
MadRadioModder