Date   
Re: Inkits India QRP kits

Art Howard
 

 Wish I was more proficient with the programs needed to do all this I certainly would help.
 

On 30 Jan 2018 2:31 am, "Mike Woods" <mhwoods@...> wrote:
A great idea Alan

I have made the page template ... now the hard part in putting it all together.  You don't want to volunteer do you?

A list of all products (WORD table you send me),  supplier, website (if there is one) and email address for contact.

73

Mike

On 30/01/18 10:43 AM, Alan de G1FXB via Groups.Io wrote:

We need a who is who, on the uBIX.net page.
So we easily know who is selling what:-

Raduino clones, Improved Raduino's, Touchscreens, AGC, S-meter, Mic Amp, Speech Processor, PA protection circuits, SWR Bridge, Auto ATU.
forgotten anything?
it's ALL TOO MUCH......  :-)


--
Mike Woods
mhwoods@...

Re: Perfect speaker grill

Giancarlo
 

Hi,

as speker grill, I have been using, in some projects, the italian moka coffee espresso spare filters,as the one reported in picture.
These are of different sizes, starting from 2 coffee cups up to 12 cups, as the one in picture. No sound problems.

The filter has a flange and it can be glued to the panel, or blocked by the speaker.

73

Gian
I7SWX

Re: Cheap Harbor Freight Case for MBITX

Art Howard
 

I guess I'm lucky I have access to a water cutter. All I have to do is draw the template and give it to a friend of mine

On 29 Jan 2018 9:50 pm, "Vince Vielhaber" <vev@...> wrote:
I've been working on a plastic one that fits both the Pelican 1150 and the Apache 1800.  I actually bought the Pelican without the pick-n-pluck.

I still need to thin it some since I found it can actually be used on the top as well if you're not putting anything real thick in it.  Some LCD displays will fit in the top with a plastic panel.

Vince.



On 01/29/2018 05:39 PM, Ken Hansen wrote:
This 'pelican-style' case is also nice - I'd love to figure out a front
panel that snaps over the bottom half of the case (remove all
pick-and-pluck)...

https://m.harborfreight.com/1800-watertight-protective-case-9-316-in-63518.html

Ken, N2VIP

On Jan 29, 2018, at 3:47 PM, wishbone_aaa <dlmock@...
<mailto:dlmock@...>> wrote:

Just place my order for a MBITX and have been looking for an
enclosure. I spotted in my workshop a Harbor Freight plastic ammo box
that looks like it will do the job.  With the lid open, the box is 6
inches deep,9 3/4 wide and 4 1/2inches high.  Price $6.99 (even
cheaper when there's a coupon).
  <https://www.harborfreight.com/catalogsearch/result/index/?dir=asc&order=EAScore%2Cf%2CEAFeatured+Weight%2Cf%2CSale+Rank%2Cf&q=ammo+box>


--
  Michigan VHF Corp.   http://www.nobucks.net/   http://www.CDupe.com/
                          http://www.metalworkingfun.com



Re: MAX9814 mic preamp and DC bias capacitor

Michael Hagen
 

I put a 1K to a 2K pot to ground.  Take the output to your capacitor from the wiper.

You can adjust all the way to ground (nothing out).

73's

Mike, WA6ISP


On 1/30/2018 8:33 AM, M Garza wrote:
Could I change R64 to a 220 ohm resistor?  I think 1k is too high.  I am using the max9814 on 40 dB and it is way too much.

Thanks,

Marco - KG5PRT 

On Jan 30, 2018 2:47 AM, "Raj vu2zap" <rajendrakumargg@...> wrote:
Just decrease the value of R63 for more gain!

At 30/01/2018, you wrote:
>uBITX Mic Audio
>
>I think that the rig only needs slightly more gain in the existing Mic PreAmp.Ā  I believe adjusting values to add gain is really all that is needed.Ā  Don't need 40 dB extra gain.





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

Re: IRF510 amplifier failures

Jerry Gaffke
 

We have thousands of uBitx's and Bitx40's out there now, an occasional post to the forum about 
a blown IRF510 is inevitable

My opinion is that SWR is not what blows the IRF510's, especially when operating from 12v.
Biggest issue is that the heatsink is quite small, especially if operating continuous duty in some digital mode
and/or feeding the IRF510's more than 12v to get higher power.
Also, be aware that the gate bias adjustments are backwards (clockwise is minimum), and get very touchy
as you approach the transition region, so once the drain current starts going up it is not much of a turn 
to go from the optimal 100ma to a very hot IRF510 with 3A of drain current.
And be aware that the heatsinks as shipped are not insulated from the IRF510 tab (connected to the drain).

I'd guess most failures are due to overheating and messing up when adjusting for 100ma of drain current.
A temp sensor and foldback current limiting would avoid these troubles if you want a safety net.
Other failures due to screwdrivers in the works or flying leads touching the wrong spot and other such snafus.

Reverse DC is not a problem for the IRF510.  It has an intrinsic reverse diode from source to drain,
will blow the traces or coils between it and the power supply.  Or, with some foresight, the fuse
you put into that power supply lead.  Where you need reverse protection is going into the remainder
of the board, be it Bitx40 or uBitx.  A 1n4148 diode would suffice, a 1n400x would not get quite so hot,
but there is no problem with running all that stuff at 0.7 volts less.  

Having a full wave rectifier in line with the power supply to the IRF510's would reduce the voltage
there by 1.4 volts.  And have a significant hit on output power available.

In post 22597, KB1GMX reports:

My experience with IRF510s is extensive and much different.  I rarely kill one even during experimenting.  I use them for RF power though 6M.  How much 8 in a parallel 4x4 push-pull at 6M running 225W!  My favorite is two in a push pull amp (K500r/wa2eby design) with 28V running about 55W on 40m and 37W at 10M and after 6 years of wrong antenna and all sorts of usual havoc its still running with the same pair. 

So the IRF510 is capable of being worked very hard, and still surviving when driving a high SWR.

Testing an antenna system with no more than 12v into the IRF510 should be fairly bulletproof.
If you want to reduce power further, reduce the drive level to the final using R136 on the Bitx40, RV1 on the uBitx.
Again, note that these pots work backwards, fully clockwise is minimum drive.

Jerry, KE7ER


On Tue, Jan 30, 2018 at 04:54 am, John Brock wrote:

I have not received my uBitx yet. I’ve been  reading this forum for about two weeks. Looks like PA failures is a huge problem.

Are the two main causes reverse DC power and high SWR?

For the DC polarity problem how about a full wave rectifier at the DC input? Two diode voltage drop a problem with this approach?

What would be the best way to limit PA  power out to a very small value to allow a manual tuner to be used for the SWR issue?

 

Re: MAX9814 mic preamp and DC bias capacitor

M Garza <mgarza896@...>
 

So, mic gain control for the win.

Thanks Mike!

Marco - KG5PRT 


On Jan 30, 2018 11:04 AM, "Michael Hagen" <motdog@...> wrote:

I put a 1K to a 2K pot to ground.  Take the output to your capacitor from the wiper.

You can adjust all the way to ground (nothing out).

73's

Mike, WA6ISP


On 1/30/2018 8:33 AM, M Garza wrote:
Could I change R64 to a 220 ohm resistor?  I think 1k is too high.  I am using the max9814 on 40 dB and it is way too much.

Thanks,

Marco - KG5PRT 

On Jan 30, 2018 2:47 AM, "Raj vu2zap" <rajendrakumargg@...> wrote:
Just decrease the value of R63 for more gain!

At 30/01/2018, you wrote:
>uBITX Mic Audio
>
>I think that the rig only needs slightly more gain in the existing Mic PreAmp.Ā  I believe adjusting values to add gain is really all that is needed.Ā  Don't need 40 dB extra gain.





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


Re: Bitx Delivered..YAY!!

F5PCX
 

Mine too : ordered 15-12, it arrived through India Post to day.
73 - Jean F5PCX.

Re: [SPAM] Re: [BITX20] IRF510 amplifier failures

Jerry Gaffke
 

Even I think that attempting to use 7400 NAND gates as linear devices is a bad idea.
As I recall, the author of the article agreed.
But a cool project regardless, rather eye-opening to see that it sort of worked.


On Tue, Jan 30, 2018 at 12:33 am, Giancarlo wrote:
I was going to build an rtx for 7MHz using 7400 N AND gates but having no test equipments except a good scope I could not experiment much. Discussing with some friends we came to the ending expecting high noise figures from such components. I used them as mixer for VFOs.

Re: IRF510 amplifier failures

Tim Gorman
 

Respectfully, current limiting in the final amp is exactly how
high-level plate modulation in an old AM transmitter works. Your audio
amplifier, which is required to generate a significant amount of power,
is transformer coupled into the plate lead of your final amplifier.
This allows the audio to vary the voltage and current in the final
amplifier turning it into a mixer. That's how you get the audio
sidebands plus the carrier that is a high level generated AM signal.

Flat-topping in a linear amplifier is actually nothing more than a form
of current limiting and it too generates spurious responses by making
the amplifier non-linear.

Before you do anything to modulate the current and voltage being fed
into a linear amplifier you should have a two-tone audio generator and
a spectrum analyzer of some kind to monitor your signal.

tim

On Mon, 29 Jan 2018 09:49:00 -0700
"Arv Evans" <arvid.evans@...> wrote:

Maybe part of the point has been missed at several levels. The
proposed current
limiter is not much different from current limiters in many commercial
power
supplies. It is not active until some current value has been
reached. Up to then
there is no current limiting or "modulation" or "compression". Yes,
the in-series
current sensing resistance does allow an output voltage drop until
voltage across
this resistance reaches about 0.65 volts to forward bias the sensing
transistor.
If your power supply output is not stiff enough to hold a steady
voltage this could
add to the sensing resistance and cause voltage droop and in really
bad cases
compression of RF output.

Question...is RF compression all that bad? It is what most transmit
ALC circuits
do. It would also be possible to make the proposed circuit driven by
reflected
power instead of current. Then we could call it a transmit ALC to
protect the
IRF510(s).

It would be fairly simple to add a latching function to the limiter
design so that it
totally shuts down output when Imax has been reached. This is
possible but would
then require a RESET button or power cycling to restore power to the
RF PA stage.

It is also possible to change the proposed design to put the current
sensing ahead
of the control MOSFET and make that MOSFET into a voltage control
circuit. This
was my initial approach but the component count became just too high
to be an
internal modification for transceivers. It would be more suitable for
converting
an unregulated power supply to a regulated one.

For those who are using modified PC power supplies it is possible to
change the
current sensing so that the switching regulator would shut down if
Imax of 2 to 3
amperes is exceeded. This approach would require power cycling to
restore operation.

Problem with using fuses is that they have a short but measurable
heating period
before they go open. When they do open they spark internally for
another short
period. Both the delay and the spark are potential problems for
circuit components.
Poly-fuse or resettable fuse devices are intended to address a
different issue.
Some are equivalent of FAST-BLOW fuses, and some are just conventional
resettable circuit breakers.

Suggestion here is that "
*if you can come up with something else that is adequate, *
*please submit a circuit drawing and explanation of how it works*" We
could all
benefit from that.

Arv K7HKL
_._


On Fri, Jan 26, 2018 at 11:27 AM, Tim Gorman <tgorman2@...> wrote:

A current "limiter" which modulates the current, i.e. limiting the
current no matter the drive level, is like applying an ALC to the
exciter. Improper design can result in compression of the signal
which can then generate spurious responses in the output.

If the current limiter is of a "drop-out" style which requires
resetting then this won't happen, it will just shut down the
exciter. In that case, however, it doesn't provide much efficiency
over a plain old fuse!

tim ab0wr

On Fri, 26 Jan 2018 05:32:08 -0800
"n5ib_2" <n5ib@...> wrote:

One other possibility to consider to protect against overcurrent
situations is to use a current limiting power supply, or add a
current limiter to an existing power supply or battery.

The current limiter circuit whose link is at this site:
<http://n5ib.net/Index.xht>
will go up to 2.2 amps, and includes a low-dropout voltage
regulator that also provides reverse polarity protection.

There is a version, in a different package, of that same regulator
chip that has an added "tracking" feature - being able to parallel
multiple chips to increase the available current. Details are on
the datasheet in the document.

Jim, N5IB





Re: Second batch of uBITX shipping? #ubitx

Tim Gorman
 

Oh wow! I remember this. For both my novice in '63 and my general in
'64!

tim ab0wr

On Tue, 30 Jan 2018 11:07:23 -0500
"David Wilcox via Groups.Io" <Djwilcox01=yahoo.com@groups.io> wrote:

What about waiting for your ham license from the FCC? IN 1960 it
took about six weeks, and there was no internet to look it up early.

Dave K8WPE

On Jan 30, 2018, at 6:54 AM, Leland Lannoye <wa9aoe@...> wrote:

So glad somebody remembers all those marketing gimmicks of Howdy
Doody and Captain Video days. My grandson doesn't even know the
difference between an and and an or gate. Perish the thought of
knowing what a transistor does.




Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Thomas Noel <tnoel@...>
Date: 1/29/18 19:49 (GMT-05:00)

Re: I did it again.. i plugged the arduino pins on reverse

César EA3IAV
 

I have checked continuity 
Orange wire and a3 from Nano continuity-> ok
And also
D7 from nano to the right last pin connector to board> ok
also connection from raduino board to main board...

i also grounded the orage wire just in case it was the mic

any hint? Maybe a blown cap? I could test resistors in raduino board were fine


Re: Second batch of uBITX shipping? #ubitx

Robert D. Bowers
 

The 6-8 week wait also was in effect in 1980!  (Another memory was having to drive to the nearest FCC facility for taking the tests, which was about an hour - on the interstate - from where I lived.)

I failed the first attempt (had to return in a month when the next tests were scheduled) because I was expecting one form of Morse code test, got another, and had a bad case of brain freeze-up when the code started flying.  (I didn't know it then, but the freeze-up was actually due to a medical issue.)

Bob  N4FBZ

On 01/30/2018 01:12 PM, Tim Gorman wrote:
Oh wow! I remember this. For both my novice in '63 and my general in
'64!

tim ab0wr

On Tue, 30 Jan 2018 11:07:23 -0500
"David Wilcox via Groups.Io" <Djwilcox01=yahoo.com@groups.io> wrote:

What about waiting for your ham license from the FCC? IN 1960 it
took about six weeks, and there was no internet to look it up early.

Dave K8WPE

On Jan 30, 2018, at 6:54 AM, Leland Lannoye <wa9aoe@...> wrote:

So glad somebody remembers all those marketing gimmicks of Howdy
Doody and Captain Video days. My grandson doesn't even know the
difference between an and and an or gate. Perish the thought of
knowing what a transistor does.




Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Thomas Noel <tnoel@...>
Date: 1/29/18 19:49 (GMT-05:00)

Audio gone on new ubitx

Erik Hokansson
 

Built the kit...audio squealed like when I built the bitx40(which I fixed )..now nothing...any other people have this issue? Suggestions?

Re: Audio gone on new ubitx

César EA3IAV
 

Solderings on the trimmer? Look for a weak connection on the volume pot

Re: Cheap Harbor Freight Case for MBITX

dj0hf
 

Wow, ordered on the 15/12 and received via India post.
I ordered on the 16/12 and haven't even had a tracking number yet.
Fingers crossed the wait won't be too much longer.

73,
Ian
DJ0HF/G3ULO

Re: Second batch of uBITX shipping? #ubitx

Steve Black
 

Don't forget the Johnson Smith catalog!!!! 1966's extraordinarily awesome smoke bomb supplier . Well they really were not that good but the waiting was the hardest part.....Steve kb1chu


On 01/30/2018 09:54 AM, mrz80 wrote:
On 01/29/2018 07:49 PM, Thomas Noel wrote:
Y'all are all so spoiled.

What's the point of even HAVING an internet connection if you can't fret, rant, and worry things to death? :D

I remember ordering from the back of comic books and cereal boxes and having to wait "allow 6-8 weeks for delivery" for my "Amazing X-Ray Glasses" or "Secret Decoder Ring".

No email, no tracking numbers.  Just endless faith and optimism.

And that was just from Kalamazoo  or Battle Creek Michigan.

If you got it at all you were amazed!

Those WERE the good old days, weren't they? Nowadays it's instant this and priority that and two days from the Asteroid Belt to your doorstep!

6-8 weeks would probably be about right. I ordered mine 12/30. Two weeks ago I was told it would be about three weeks 'til it shipped, which ought to put it on my front porch between 6-8 weeks from when I ordered. :D


Re: IRF510 amplifier failures

Arv Evans
 

I give up!  Maybe this IRF510 failure thing is a non-problem.

Someone recently suggested adding a 1K resistor across the
antenna connection to limit really high SWR situations.  That
sounds interesting.

Arv  K7HKL
_._


On Tue, Jan 30, 2018 at 11:08 AM, Tim Gorman <tgorman2@...> wrote:
Respectfully, current limiting in the final amp is exactly how
high-level plate modulation in an old AM transmitter works. Your audio
amplifier, which is required to generate a significant amount of power,
is transformer coupled into the plate lead of your final amplifier.
This allows the audio to vary the voltage and current in the final
amplifier turning it into a mixer. That's how you get the audio
sidebands plus the carrier that is a high level generated AM signal.

Flat-topping in a linear amplifier is actually nothing more than a form
of current limiting and it too generates spurious responses by making
the amplifier non-linear.

Before you do anything to modulate the current and voltage being fed
into a linear amplifier you should have a two-tone audio generator and
a spectrum analyzer of some kind to monitor your signal.

tim

On Mon, 29 Jan 2018 09:49:00 -0700
"Arv Evans" <arvid.evans@...> wrote:

> Maybe part of the point has been missed at several levels.  The
> proposed current
> limiter is not much different from current limiters in many commercial
> power
> supplies.  It is not active until some current value has been
> reached.  Up to then
> there is no current limiting or "modulation" or "compression".  Yes,
> the in-series
> current sensing resistance does allow an output voltage drop until
> voltage across
> this resistance reaches about 0.65 volts to forward bias the sensing
> transistor.
> If your power supply output is not stiff enough to hold a steady
> voltage this could
> add to the sensing resistance and cause voltage droop and in really
> bad cases
> compression of RF output.
>
> Question...is RF compression all that bad?  It is what most transmit
> ALC circuits
> do.  It would also be possible to make the proposed circuit driven by
> reflected
> power instead of current.  Then we could call it a transmit ALC to
> protect the
> IRF510(s).
>
> It would be fairly simple to add a latching function to the limiter
> design so that it
> totally shuts down output when Imax has been reached.  This is
> possible but would
> then require a RESET button or power cycling to restore power to the
> RF PA stage.
>
> It is also possible to change the proposed design to put the current
> sensing ahead
> of the control MOSFET and make that MOSFET into a voltage control
> circuit. This
> was my initial approach but the component count became just too high
> to be an
> internal modification for transceivers.  It would be more suitable for
> converting
> an unregulated power supply to a regulated one.
>
> For those who are using modified PC power supplies it is possible to
> change the
> current sensing so that the switching regulator would shut down if
> Imax of 2 to 3
> amperes is exceeded.  This approach would require power cycling to
> restore operation.
>
> Problem with using fuses is that they have a short but measurable
> heating period
> before they go open.  When they do open they spark internally for
> another short
> period.  Both the delay and the spark are potential problems for
> circuit components.
> Poly-fuse  or resettable fuse devices are intended to address a
> different issue.
> Some are equivalent of FAST-BLOW fuses, and some are just conventional
> resettable circuit breakers.
>
> Suggestion here is that "
> *if you can come up with something else that is adequate, *
> *please submit a circuit drawing and explanation of how it works*"  We
> could all
> benefit from that.
>
> Arv  K7HKL
> _._
>
>
> On Fri, Jan 26, 2018 at 11:27 AM, Tim Gorman <tgorman2@...> wrote:
>
> > A current "limiter" which modulates the current, i.e. limiting the
> > current no matter the drive level, is like applying an ALC to the
> > exciter. Improper design can result in compression of the signal
> > which can then generate spurious responses in the output.
> >
> > If the current limiter is of a "drop-out" style which requires
> > resetting then this won't happen, it will just shut down the
> > exciter. In that case, however, it doesn't provide much efficiency
> > over a plain old fuse!
> >
> > tim ab0wr
> >
> > On Fri, 26 Jan 2018 05:32:08 -0800
> > "n5ib_2" <n5ib@...> wrote:
> >
> > > One other possibility to consider to protect against overcurrent
> > > situations is to use a current limiting power supply, or add a
> > > current limiter to an existing power supply or battery.
> > >
> > > The current limiter circuit whose link is at this site:
> > > <http://n5ib.net/Index.xht>
> > > will go up to 2.2 amps, and includes a low-dropout voltage
> > > regulator that also provides reverse polarity protection.
> > >
> > > There is a version, in a different package, of that same regulator
> > > chip that has an added "tracking" feature - being able to parallel
> > > multiple chips to increase the available current. Details are on
> > > the datasheet in the document.
> > >
> > > Jim, N5IB
> > >
> > >
> > >
> >
> >
> >
> >
> >





Re: Audio gone on new ubitx

Erik Hokansson
 

Tried another pot ..ran wires from the board..tried head phones...still nothing..not sure what I should check on the audio circuit..

Re: uBITX woes, feeling disheartened. #ubitx

K5ESS
 

The pin numbering on these relays is inconsistent  i.e. reversed in some cases. Either will work OK by taking this into consideration.

Mike

K5ESS

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of David Beal
Sent: Tuesday, January 30, 2018 9:36 AM
To: BITX20@groups.io
Subject: Re: [BITX20] uBITX woes, feeling disheartened.

 

Hi Nick, 

I got the same relay and am equally confused as the pinout for both the original relay (Virtual) and this replacement (Panasonic) appears to be the same (across 1/16 on both pinouts); yet the schematic shows the coil across pin 8/9 per:  https://groups.io/g/BITX20/message/40439

Oddly, the data sheet for this relay which I posted here: https://groups.io/g/BITX20/message/40440  is no longer available.  
Further, this post:  https://groups.io/g/BITX20/message/26983  indicates coil across 1/16 also. 

I'm going to disconnect PA power this weekend and use an ohm meter to trace through the relays per someone else's suggestion.  

Dave


--
Dave Beal
AE6RQ

Re: Audio gone on new ubitx

César EA3IAV
 

Do you still have the lcd working? If so, does the radio work but without sound? 
Maybe the ptt is activated....