Date   
Re: uBITX shipping time

a.vision
 

Hi my ubitx was posted via India mail on the 12th April and received today on the 14th just 2 working days and no customs charges brilliant now the fun begins.

On 13 April 2018 at 06:38 "a.vision via Groups.Io" <a.vision@...> wrote:

Hi ordered my ubitx on 15th February and received shipping notice yesterday look forward to delivery now shipped via India post.The only thing that I found dissapointing is that people who ordered their ubitx after me were being shipped before me . 







Sent from Samsung tablet
 


-------- Original message --------
From: "Don N9GOD via Groups.Io" <n9god@...>
Date: 12/04/2018 20:01 (GMT+00:00)
To: BITX20@groups.io
Subject: Re: [BITX20] uBITX shipping time

Looks like shipping is catching up. My ubitx ordered Mar 1 shipped today Apr 12
--
check http://n9god.com for electronics publication in English and Foreign formats


 

Re: TDA2822 fried

philip yates
 

Mine has FCI and Pl1 then TDA2822M on it, have had it on RX for quite some time.

Phil - G7BZD

On Sat, Apr 14, 2018 at 8:17 AM, Raj vu2zap <rajendrakumargg@...> wrote:
WX is the marking.

Ideally cut the 12V track and feed 9V from a regulator. I use a 78L09 soldered on to the board as a hear sink.
You can use a 7809 or 7808 on the chassis and run a wire.

Raj

At 14/04/2018, you wrote:
Do we know what the markings are on the faulty IC's

Phil - G7BZD

On Sat, Apr 14, 2018 at 5:18 AM, Mvs Sarma <mvssarma@...> wrote:
Nice PAUL,
 Don't just increase volume much and don't immediately use ear / headphones. Many buyers, are perhaps not using the experiences  of others. The do irrelevenat and then only relaise after frying the TDA. Perhaps one can pre install a 6V regulator before starting the rig and save the device.

all the best
sarma
 vu3zmv



Â

Regards
MVS Sarma
Â

On Sat, Apr 14, 2018 at 2:16 AM, Paul N2QXB <n2qxb@...> wrote:
Just got my package  and so glad that the chip now has a socket



Re: TDA2822 fried

 

WX is the marking.

Ideally cut the 12V track and feed 9V from a regulator. I use a 78L09 soldered on to the board as a hear sink.
You can use a 7809 or 7808 on the chassis and run a wire.

Raj


At 14/04/2018, you wrote:
Do we know what the markings are on the faulty IC's

Phil - G7BZD

On Sat, Apr 14, 2018 at 5:18 AM, Mvs Sarma <mvssarma@...> wrote:
Nice PAUL,
 Don't just increase volume much and don't immediately use ear / headphones. Many buyers, are perhaps not using the experiences  of others. The do irrelevenat and then only relaise after frying the TDA. Perhaps one can pre install a 6V regulator before starting the rig and save the device.

all the best
sarma
 vu3zmv



Â

Regards
MVS Sarma
Â

On Sat, Apr 14, 2018 at 2:16 AM, Paul N2QXB <n2qxb@...> wrote:
Just got my package  and so glad that the chip now has a socket


Re: TDA2822 fried

philip yates
 

Do we know what the markings are on the faulty IC's

Phil - G7BZD

On Sat, Apr 14, 2018 at 5:18 AM, Mvs Sarma <mvssarma@...> wrote:
Nice PAUL,
 Don't just increase volume much and don't immediately use ear / headphones. Many buyers, are perhaps not using the experiences  of others. The do irrelevenat and then only relaise after frying the TDA. Perhaps one can pre install a 6V regulator before starting the rig and save the device.

all the best
sarma
 vu3zmv



 

Regards
MVS Sarma
 

On Sat, Apr 14, 2018 at 2:16 AM, Paul N2QXB <n2qxb@...> wrote:
Just got my package  and so glad that the chip now has a socket



Re: TDA2822 fried

MVS Sarma
 

Nice PAUL,
 Don't just increase volume much and don't immediately use ear / headphones. Many buyers, are perhaps not using the experiences  of others. The do irrelevenat and then only relaise after frying the TDA. Perhaps one can pre install a 6V regulator before starting the rig and save the device.

all the best
sarma
 vu3zmv



 

Regards
MVS Sarma
 

On Sat, Apr 14, 2018 at 2:16 AM, Paul N2QXB <n2qxb@...> wrote:
Just got my package  and so glad that the chip now has a socket


Re: #uBiTx CW RF power out #ubitx

Alan -MMØWXT
 

On Mon, Mar 5, 2018 at 07:46 pm, Jerry Gaffke wrote:
Set bias for 100ma of drain current on each IRF510 using RV2 and RV3 and then leave it be.
That 100ma shouldn't change much even if you were to go from a 12v PA-PWR to 24v. 

Adjust power level using RV1 on the uBitx.  (RV1 sets IRF510 drain current on the Bitx40)
For SSB, could also vary power level by adjusting the mike gain at Q6 somehow.

I assume the smoked U1 was marked "WX".  Can you verify?
The WX clones blow for no particular reason.
The WX probably works reliably if the supply voltage is reduced to 5v or so, down from 12v.
Search for "TDA2822" in this forum to see some nice long discussions
The NTE7155 will probably work fine, perhaps you could report back on that too.

> The first signal reports were the audio was poor with too much high frequencies and no mid to low.

Sounds like the 12mhz bfo is positioned incorrectly relative to the passband of the crystal filter.
Should be able adjust your audio (both transmit and receive, affects both equally)
by using the calibration routine in the Raduino for the bfo frequency adjust.

Jerry, KE7ER


On Mon, Mar 5, 2018 at 07:23 pm, Bob wrote:

My question is how to set the maximum power? Use Rv2 and Rv3 to set the bias or use Rv1 to back off the drive after the bias has been set using Rv2 and Rv3.

 


 Hi Jerry I have an FCI/FOI TDA in my ubitx batch 2. It is very hot indeed after rig on for an hour.is there an over voltage issue to the chip?

Thank you again for all your help getting it going again with the RF510.
--
MMØWXT
GQRP - #15057

Re: #uBiTx CW RF power out #ubitx

Alan -MMØWXT
 

I can agree. The vast amount of help received Seems to have got me sorted with rf at the dummy load. Just now to get it on air for a signal report.

--
MMØWXT
GQRP - #15057

Re: VK4PLN's Radrino replacement boards

K9HZ <bill@...>
 

Thanks Nick.  MUCH easier on the eyes…

 

 

Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

 

Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

 

Owner – Operator

Villa Grand Piton – J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com

Like us on Facebook! facebook icon

 

Moderator – North American QRO Group at Groups.IO.

 

email:  bill@...

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Nick VK4PLN
Sent: Friday, April 13, 2018 6:22 PM
To: BITX20@groups.io
Subject: Re: [BITX20] VK4PLN's Radrino replacement boards

 

Here we go folks:


73


Virus-free. www.avg.com

Re: VK4PLN's Radrino replacement boards

Nick VK4PP
 

PDF Version

Re: VK4PLN's Radrino replacement boards

Nick VK4PP
 

Here we go folks:


73

TDA2822 -- what's a vendor to do?

Jim Strohm
 

Hi

This is kind of an Ashhar question....

What's to become of all those fast-failing TDA2822 chips?
Has the vendor offered any compensation?  The main reason I'm asking is -- I've been in a number of positions, both professionally and as a hobbyist, when something went wrong at a scale like this -- approaching unity failure -- and I'm wondering whether either the vendor or the manufacturer has done anything regarding a full-scale make-good.

At my current company (no, I cannot offer any more details) a vendor of a user-level component suddenly started shipping their assembled interface devices that randomly failed.  Well, more like "most of the time" and not just "randomly."

The closest I've seen to that problem is the counterfeit FTDI serial-to-USB chips that plagued us amateurs a few years ago.  FTDI never offered a make-good, and most of the end-user companies didn't, either. 

So, Ashhar, has your vendor offered any recompense yet?

73
Jim N6OTQ

I've already suggested that your issue and the FTDI issue be considered in my company's resolution. 

 

update to KD8CEC 1.061 firmware user manual

Rod Davis
 

Hi All,

attached is an updated user manual for the KD8CEC 1.061 firmware.

The updates were to

1. incorporate feedback received on the manual, with some new
    operating tips,and

2. enhance the Memory Manager section a bit, and

3. improve readability.


As before, please send any feedback to the email address shown in the manual.


A new manual for KD8CEC firmware rev 1.07 is forthcoming, as is a manual on the Memory Manager.

Regards,

Rod KM6SN


Re: AGC circuit to try?

ajparent1/kb1gmx
 

Lawrence,

So happens I'have all the mobile manuals and the SSB for radio amateurs since they were printed...

Yes its a good circuit, low noise and wide agc range.  HyCas is a variation of that as well as others.
It can easily be done with a pair of J310s just as well.  The 3n128 disappeared in the 70s but it was
used back then as it had a gm far higher than Jfets of the day.  Now we have better.

Its weaknesses are that the input match is nonexistant.  It does not make for a good match for
any filter unless loaded with a resistor and matched with a step up transformer.  Its output match is
also uncontrolled so  buffering is needed between it and filters note the source follower for that. 
Things we learned since then.  The reason it was done with preselectors is SWBC, short wave
broadcasters were far more common back then.  So selectivity as close to the antenna was the 
design methodology of the day (usually meant the crystal filter) and often the front ends were
doubled tuned for selectivity within the band.

I have 4 radios from the early era of transistors I still use.  Two the Tentec 505(Argonaut) and 340(Triton)
used circuits like that with  tuned preselectors.  They are both very good but current radios are better.
A receiver that has a front end using two fets cascade  is the AX190 I have, also does well on the bands
40+ years after I got it.

It would be good in front of the Minima receiver but for uBitx switching it out would be a pain never mind
the tuning requirements over the full working range of the uBitx.

Allison

Re: ubitx keyer

Jack, W8TEE
 

The Greater Cincinnati Builders Group is actually doing our Pixie build on the 21st. I'll let the group know how it goes.

Jack, W8TEE


On Friday, April 13, 2018, 4:49:21 PM EDT, Jim Stafford <qrp@...> wrote:


I also agree that the Pixie is less than a CPO.  We have done this a couple times at schools
we work with.  It's a lot of fun. Garry, AK4NA, is arranging 10 Pixies for the school he supports
for them to send to each other and do CODE practice.  nfarl.org

jim/w4qo
CU at FDIM

Re: ubitx keyer

Jim Stafford W4QO
 

I also agree that the Pixie is less than a CPO.  We have done this a couple times at schools
we work with.  It's a lot of fun. Garry, AK4NA, is arranging 10 Pixies for the school he supports
for them to send to each other and do CODE practice.  nfarl.org

jim/w4qo
CU at FDIM

Re: TDA2822 fried

Paul N2QXB <n2qxb@...>
 

Just got my package  and so glad that the chip now has a socket

Re: AGC circuit to try?

Lawrence Galea
 

Part 3

On Thu, Apr 12, 2018 at 2:48 PM, ajparent1 <kb1gmx@...> wrote:
ARRL Single Sideband for the Radio Amateur 1970 p193 et seq.
"An Engineer's Ham-Band Receiver"

I've duplicated the PLL for another radio and copied ideas for radios I have built.
They worked very well.

Three reasons its not a fit for uBITx......
One: the MOSFets used disappeared in the late 70s.
Two: Its a narrow band front end using varicap tuning, usually called a preselector. Lots of band coils.
Three: is it would require much switching to take it out of the transmit path.

Allison


Re: AGC circuit to try?

Lawrence Galea
 

Part 2

On Thu, Apr 12, 2018 at 2:48 PM, ajparent1 <kb1gmx@...> wrote:
ARRL Single Sideband for the Radio Amateur 1970 p193 et seq.
"An Engineer's Ham-Band Receiver"

I've duplicated the PLL for another radio and copied ideas for radios I have built.
They worked very well.

Three reasons its not a fit for uBITx......
One: the MOSFets used disappeared in the late 70s.
Two: Its a narrow band front end using varicap tuning, usually called a preselector. Lots of band coils.
Three: is it would require much switching to take it out of the transmit path.

Allison


Re: AGC circuit to try?

Lawrence Galea
 

Ge evening Allison.
I mentioned it because of the two fets used in cascade at the front end and the use of agc.
It's design being nearly 50 years old is a totally different concept.
As you said the semiconductors are obsolete but one could use modern ones if they want to do so.
However, I have scanned the article which is hereto attached.
I scanned it at 600 dpi so I had to split it into three PDF files because of the 20 Mb attachment limit. 
Regards to all.
Lawrence

On Thu, Apr 12, 2018 at 2:48 PM, ajparent1 <kb1gmx@...> wrote:
ARRL Single Sideband for the Radio Amateur 1970 p193 et seq.
"An Engineer's Ham-Band Receiver"

I've duplicated the PLL for another radio and copied ideas for radios I have built.
They worked very well.

Three reasons its not a fit for uBITx......
One: the MOSFets used disappeared in the late 70s.
Two: Its a narrow band front end using varicap tuning, usually called a preselector. Lots of band coils.
Three: is it would require much switching to take it out of the transmit path.

Allison


Re: [qrp-tech] DC-DC converter experiment

Jack, W8TEE
 


It might be the DDS/VFO board we did for the QST article (March, 2015) on the Forty-9er. The only touchy thing about the buck converter was the Phillips head screw that adjusts the voltage which was easily torqued right off the board.

Jack, W8TEE


On Friday, April 13, 2018, 1:59:02 PM EDT, Nick Kennedy <kennnick@...> wrote:


I used one that looks a lot like that on a project with a DDS and Arduino
Nano. It was a hair smaller than a postage stamp. The input voltage came
from 6-NiMh cells and the output is steady at 5 V. Efficiency is high too.

From my notes:

I tested the little regulator, which is the size of a postage stamp. While
supplying 190 mA at 5 VDC with input voltage varying from 8.4 to 5.5 VDC
the efficiency was 87% to 93%.  Over the expected range of 8.4 V to 6.3 V,
it’s 87% to 91%. It started to drop out at 5.4 volts input, but otherwise
the output was rock steady over the input voltage range. It’s rated for 5.5
V to 12 V input and 3A output.
72-

Nick, WA5BDU


On Fri, Apr 13, 2018 at 12:14 PM, chuck adams <chuck.adams.k7qo@...>
wrote:

> Since I have to wait on the slow boat to test this, maybe one of you has
> a similar item and can report to the group.
>
> Here is a DC-DC converter for down conversion and costs $0.79.
>
> http://tinyurl.com/ybp8hsnj
>
> I have no problem whatsoever with spending the $0.79 USD to try it
> and I can, of course, find another use for the critter in powering 3.3V
> DDS modules.  I just would have to wait 4 weeks for the critter to swim
> across the Pacific ocean and maybe take a few days in KH6 land for DX.
>
> ​...​
>
>
> Any one gone and played with one of these DC-DC converters in a
> similar manner?
>
> chuck, k7qo
>
>
>