Date   
Re: tx pop

Nick VK4PP
 

Hi Again,
Im just looking over this and trying to understand what is happening here, Im still learning all this stuff...

So on TX the fet is activated via the 300K resistor, that causes the audio signal at Pin 7 on U1 to be grounded out, effectivly muting it somewhat, except for the loud CW tone comming via the decrease 1K resistor R253.
When switching back to RX, the Cap holds the mosfet closed for a fraction longer, the diode is to stop the charge feeding back to the TX/RX circuit?

73 VK4PLN

Re: #ubitx Powering options? #ubitx

Jerry Gaffke
 

More to the point, any unusual currents in paralleled batteries are a one time event,
and only occur if the batteries did not start out in an equal charge state.

I'm assuming the batteries are well matched.  There are additional currents
if they are not matched.  For example, the battery with less internal resistance
will deliver more power to the load, and once the load is gone might be recharged by the other.
But within certain limits that is not a bad practice. 

Definitely not a good practice to be paralleling batteries that have
significantly different voltages at the terminals.  
Easy to disregard if you are in a hurry and/or don't know what's at stake.
As I stated before, with some types of batteries the results could be catastrophic.
 
Like so many things in life, if you don't know what you are doing
then paralleling batteries is not a good practice.


On Mon, Jan 15, 2018 at 07:23 pm, Jerry Gaffke wrote:
Once equalized, there are no currents eating anything up.

Re: tx pop

Nick VK4PP
 

Excellent, Thanks, Did you just reuse the C78? What is its value?

Also I notice the C78 Is not on the Schematic (comming off Pin7 to Vol-M),

73, Nick VK4PLN

Re: Programming Raduino help

Vince Vielhaber
 

Try a different cable. Many USB cables were originally intended to only be for charging and only have the power connections, no data. The IDE should see the raduino.

Vince.

On 01/15/2018 10:24 PM, Vic WA4THR via Groups.Io wrote:
Thanks, Jack. I did that and it reported the drivers were there, but the
Raduino still does not show up in either the IDE nor in the hardware
devices when I go to system info. It is getting power from the USB port,
and lights up and starts, but that's it. I did select Arduino Nano from
the board list following the "Geezers" instruction, not Uno as mentioned
in the IDE help file.

If the Raduino board is bad, is it possible to order a new one? The
display seems to be working fine, and it is controlling the BitX40 as
expected, but part of the attraction was the ability to try software
hacks, and if I can't address it...

=Vic=

Re: Matched xtals #ubitx #bitx40

Jerry Gaffke
 

A wandering center frequency for the crystal filter could be compensated for by re-programming 
the BFO and the second local oscillator, both coming out of the si5351 on the uBitx.


On Mon, Jan 15, 2018 at 06:58 pm, DuWayne Schmidlkofer wrote:
The filter was developed by Lee Jones of TenTec, and patented in 1991, ande commonly as a Jones filter.  It has been used by TenTec, Elecraft and several others.
The problem most often found is that the center frequency changes slightly when the bandwidth is changed.  There was a modification to this design that corrected this in a magazine article a few years ago.  I will try to find it and post more information. 
--
DuWayne  KV4QB

Re: Programming Raduino help

Vic WA4THR
 

Thanks, Jack. I did that and it reported the drivers were there, but the Raduino still does not show up in either the IDE nor in the hardware devices when I go to system info. It is getting power from the USB port, and lights up and starts, but that's it. I did select Arduino Nano from the board list following the "Geezers" instruction, not Uno as mentioned in the IDE help file.

If the Raduino board is bad, is it possible to order a new one? The display seems to be working fine, and it is controlling the BitX40 as expected, but part of the attraction was the ability to try software hacks, and if I can't address it...

=Vic=

Re: #ubitx Powering options? #ubitx

Jerry Gaffke
 

If one battery starts out at a slightly lower voltage than the other,
then the higher voltage battery will charge the lower voltage battery until they are equal.
Once equalized, there are no currents eating anything up.
What's more, no power was lost, other than the usual charge/discharge inefficiencies of the batteries.


On Mon, Jan 15, 2018 at 06:51 pm, Michael Hagen wrote:

It is really not a good practice, why would you want circulating currents eating up batteries until equilibrium is met?

 

Re: #ubitx Power Supply For uBitx? #ubitx

Jerry Gaffke
 

12v at 5A = 60 Watts, more than enough if powering the IRF510 finals from 12v.

If you plan  to someday use that 12v supply to power a boost mode switching power supply 
that generates 24v for the IRF510's, then 5 Amps is marginal, you might want more like 10A.


Perhaps more than you want to know:

UBitx power output at 12v is around 10 Watts, maybe a bit more.
The IRF510's are about 50% efficient, so 20 Watts into the IRF510's, and the rest of the
rig probably needs about 5W.   So will draw around 25 Watts from your 60 Watt supply.

Power out of the IRF510's is proportional to the square of the voltage
there are some losses involved so it really wont' rise that high.
But this means that if you double the voltage to the IRF510's from 12 to 24v,
the power into the IRF510's may rise from 20 Watts to as much as 80 Watts.
Exceeding the capabilities of your 60 Watt 12v supply.
So maybe you need a 10A supply?

It might be possible to get a power supply for free from an old computer.
These often have multiple 12v outputs, each giving 10 or 20 Amps.
There are notes on the web for how to make use of such a beast as a 12v bench supply.
Primary issue is that it may create too much interference for the receiver
without extra filtering.   With some work it may be possible to create a 24v output
by running two 12v ;output windings in series.  This would require cutting one of
those windings free from the power supply's ground reference, and may not be trivial to do.

Be sure to include fuses, perhaps 0.5A into the main uBitx board and a separate fuse
into the IRF510 finals. A 3 Amp fuse should be sufficient if operating the IRF510's from 12v.


On Mon, Jan 15, 2018 at 06:01 pm, Michael Monteith wrote:
My thought is probably a 12v 5A power supply.  

Re: Matched xtals #ubitx #bitx40

DuWayne Schmidlkofer
 

The filter was developed by Lee Jones of TenTec, and patented in 1991, ande commonly as a Jones filter.  It has been used by TenTec, Elecraft and several others.
The problem most often found is that the center frequency changes slightly when the bandwidth is changed.  There was a modification to this design that corrected this in a magazine article a few years ago.  I will try to find it and post more information. 
--
DuWayne  KV4QB

Re: Matched xtals #ubitx #bitx40

Vince Vielhaber
 

There's also a manual for the Druzhba radio with schematic here:

https://docs.wixstatic.com/ugd/69b585_f90fa858dbb54de2a7eec046267c06c6.pdf

Vince.

On 01/15/2018 09:16 PM, n2vdy via Groups.Io wrote:
On the rv3yf page there is a link to a manual for the Klopik radio. The
schematic for the filter is the same. There are YouTube videos showing
the radios in use.

On Mon, Jan 15, 2018 at 05:51 pm, Arv Evans wrote:

N2VDY

It would be interesting to see a schematic of that crystal filter
that uses diodes to vary the bandwidth.

https://www.ebay.com/itm/Amateur-ham-radio-HF-Transceiver-Druzhba-M-MotherBoard-v4-6-KIT-/172451108452

https://www.rv3yf.store/bandpass-and-lowpass-filters

I recognize some, but not all, of their products as being the work
of Wim SP5DJJ.

Their web site is very slow so you need some patience to wait for
things to become visible.

Arv K7HKL
_._


On Mon, Jan 15, 2018 at 5:58 PM, n2vdy via Groups.Io
<n2vdy=yahoo.com@groups.io <mailto:n2vdy=yahoo.com@groups.io>> wrote:

I have a Russian radio kit I haven't put together yet called the
Druzhba-M. It has a crystal filter with varactor diodes that it
uses to vary the bandwidth of the filter.









Re: tx pop

Ryhor Harbacheuski
 

no problem, it's attached.
I believed this is very similar to what some folks used to kill BITX40
pop earlier.
The key here is to open the mosfet as soon as TX is on and to keep it
open a bit longer after going back to RX.
Mosfet is BS170
I feel this mod is very beneficial especially for CW - pops are
particular bothersome while keying.
Once again, this mod will decrease volume of cw tone, so some tweaking
or R253 may be necessary.
Funny enough in my case R253 was mistakenly 1K instead of 10K which
turned out to be just right after the mod was done.
Thank you Farhan for delivering this beautiful baby to us
Greg W3NW

On Mon, Jan 15, 2018 at 3:16 PM, <nickpullen@...> wrote:
Hi, would you be able to provide a schematic for this Mod please?

Re: #ubitx Powering options? #ubitx

Michael Hagen
 

It is really not a good practice, why would you want circulating currents eating up batteries until equilibrium is met?

Ford made the decision to do it?  They had their reasons.

For Me, I would have never done it.  And I worked for Ford Aerospace for  a lot of years.  Yep, wonderful Newport Beach, Ca.

I did not to get in on that decision, they probably would not want my comments!.  It is not the right thing to do?

I guess if it works, OK?  They have sold lots of trucks.

Just buy  both batteries when you change.  Hope they are matched?  $150 ea.

Mike, WA6ISP






On 1/15/2018 5:47 PM, Jerry Gaffke via Groups.Io wrote:
You're right, it's not a good idea to blindly parallel a bunch of batteries. 
But it can work just fine if they are of the same size and age and charge state.

If one has more internal resistance, that just means the other one will be doing more of the work.

However, if you connect them when not equally charged, one will charge the other.
In some cases the currents involved while the charge states equalize are excessive, far beyond
what either battery is rated for.  Could easily have an explosion.
Something to keep in mind, especially with Li-Ion batteries or large lead acid batteries.

Once the batteries in parallel reach the same charge state, there won't be any 
currents bouncing around. 
 
I have several of LED headlamps I bought on the web. 
Each has two 18650 Li-Ion batteries in parallel, they feed the LED through a resistor.
I doubt these particular 18650's have any kind of over-current protection, as the headlamps were quite cheap.
Use them all the time, work great.  And keep their charge just fine when sitting on the shelf.

We're off grid, I started out with  used golf cart batteries, wiring up multiple banks in parallel.
Around 10 KWH worth total, all having different histories and ages.
If anything, any extra internal resistance due to aging would have helped prevent excessive currents
if I had connected them in parallel without first bothering to check if the voltages were reasonably close.

Jerry, KE7ER


On Mon, Jan 15, 2018 at 04:14 pm, Michael Hagen wrote:
You do not want to parallel batteries, difference in internal resistance will cause one to try to charge another, and around we go, a circulating current between the batteries that will run them both down.  And we don't even get to use the power!

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

Re: uBITX woes, feeling disheartened. #ubitx

Jim Sheldon
 

Wow Nick, I had never thought of using a vacuum cleaner to suck off the solder!  There should be plenty of suction there for that and you could use some of that silicone tubing they use at the end of those spring loaded solder suckers to keep it from getting melted by the Iron.  The vacuum cleaner idea would also work quite well for getting surface mount components off a board using one of those hot air rework stations for the heat.

Thanks for a super idea and I'll have to build up something for my Shop Vac to do just this!

Jim Sheldon - W0EB

------ Original Message ------
Sent: 1/15/2018 8:31:02 PM
Subject: Re: [BITX20] uBITX woes, feeling disheartened.

2 Tips for you with replacing the relay.;

1: Check the new relay isnt polaraized before you install it.... see my experience...
2: A method i use to remove solder is to connect up a 8mm tube to the vacume cleaner via an adapter, and heat up the solder pad, then quickly suck the liquid solder away from each hole, works rather well...

Re: A little off Topic? SDR Program PC?

James Lynes
 

Mike:

I use gqrx on Ubuntu 14.04LTS.

I believe there are Windows and Mac versions. There is a RPI version also. Add a heatsink and fan to the board.

James

Re: A little off Topic? SDR Program PC?

Vince Vielhaber
 

You could always put Linux on it and run CubicSDR. I have one of those $20 SDR units with only a single SMA and Cubic runs it just fine.

Vince.

On 01/15/2018 08:05 PM, Michael Hagen wrote:
I got one of those black boxes with a SDR inside. It does not have the
down converter as some, you change the parameters
in the program to get HF. It has 2 SMAs, HF, and then above.
I got it to work with SDR Sharp (#) on my PC. It is running W10. I
like it. Less than $30 for the Radio? Still need some kind of outside
antenna?

The website says SDR# does not work anymore for XP.
My Old laptop is XP, anyone know which program with the least problems
works for XP?
Any one with this experience?

73's
Mike, WA6ISP

Re: uBITX woes, feeling disheartened. #ubitx

Nick VK4PP
 

2 Tips for you with replacing the relay.;

1: Check the new relay isnt polaraized before you install it.... see my experience...
2: A method i use to remove solder is to connect up a 8mm tube to the vacume cleaner via an adapter, and heat up the solder pad, then quickly suck the liquid solder away from each hole, works rather well...

Re: uBITX woes, feeling disheartened. #ubitx

David Beal
 

Thank you so much Nick and Raj - 

Apparently, my brain went on for lunch and forgot to tell my body. 

I measure 0.3 ohms PTT ON and also OFF. 

A new relay should be here in a week or so. 
 

--
Dave Beal
AE6RQ

Re: Matched xtals #ubitx #bitx40

Jerry Gaffke
 

Farhan's notion of having a second ladder filter for CW in parallel with the 12mhz SSB filter seems a great solution.
He suggested going down to 1.8mhz or so for the CW filter as I recall,
the lower frequency of operation means the bandwith will be correspondingly smaller.
Should match the 200 ohm impedance of the present filter (or perhaps use additional transformer windings?).

The impedance of these ladder filters is very high for anything out of band, so the two filters do not interfere.
Switch filters by moving the second local oscillator.
 
I think someone in the forum has implemented this, said it worked fine
 

Re: #ubitx Powering options? #ubitx

Vince Vielhaber
 

Forgot about this point. $150 is cheap. I just spent $170 (inc tax) for one for my Durango. 5 year warranty tho, 3 year direct replacement.

Vince.

On 01/15/2018 07:46 PM, Michael Hagen wrote:

Glad I only have one at $150 ea!

Mike

Re: #ubitx Powering options? #ubitx

Vince Vielhaber
 

Ford? NEVER! '97 Dodge Ram. These were bought together so when they go bad they go back to O'Reilly together and new ones follow me home. Heavy things are easy to lift around here... I have a hilo!

Vince.

On 01/15/2018 07:46 PM, Michael Hagen wrote:
Probably Ford?

The proper way is to have a 24V starter, and they are put in series for
Start? Then charged though isolation diodes?

I think GM did that for Mil Trucks? Not sure though?

I bet you have to buy both NEW batteries of same make at same time?

You would not want an old one and new one paralled?

I just thought about when I changed my battery in my F150 4WD a year ago.

I could not properly lift it UP over the Fender (lifted 4WD). I have
to use a blanket not to scrape the paint!

They are sooo Heavy!

Glad I only have one at $150 ea!

Mike



On 1/15/2018 4:30 PM, Vince Vielhaber wrote:
My diesel truck has paralleled batteries. They go dead from time to
time but it's from other things dragging them down before doing it to
each other.

Vince.

On 01/15/2018 07:14 PM, Michael Hagen wrote:
You do not want to parallel batteries, difference in internal resistance
will cause one to try to charge another, and around we go, a circulating
current between the batteries that will run them both down. And we
don't even get to use the power!

I think they did this on some vehicles like diesel trucks, I would think
you would want to disconnect them when not being charged?

I am not an expert on this, just seems bad?

73's

Mike, WA6ISP


On 1/15/2018 3:57 PM, Simon Rumble wrote:
Thanks Jerry that's exactly the flaw in my thinking right there! It
did seem a bit good to be true. So series wiring increases voltage but
not capacity. Makes sense.

Amending my spreadsheet, two lantern batteries (6V, 26 Ah) might be
the best option. Alternatively I'll have a look at some rechargeable
options but I'm not sure I'll be able to sort that by the end of the
week.

On Tue, 16 Jan 2018 at 10:22 Jerry Gaffke via Groups.Io
<jgaffke=yahoo.com@groups.io <mailto:yahoo.com@groups.io>> wrote:

Simon,

If you stack eight 1.8AH at 1.5V batteries in series, you get
12V at 1.8AH.
They would have to be in parallel to get 14.4AH, but then you only
have 1.5V.

Also, those AH ratings are typically for 20 hour discharge rates,
if you are sucking a couple amps they will fold up in minutes.
And battery current will get worse if you bump up power by using a
boost converter
to power the IRF510.

I'd recommend jacking into the cigarette lighter for 12v if you
are driving, bring a long cord.
If a short hike and a long operating session, maybe get a $20 lead
acid riding lawnmower battery.
Or use the Li-Ion battery pack from a drill motor or impact driver.

Avoid feeding your rig much more than 12v.

Jerry, KE7ER



On Mon, Jan 15, 2018 at 03:01 pm, Simon Rumble wrote:

So my question is about off-grid power. Can I get away with 8x
AA batteries in series or should I use a step up converter to
keep the voltage up? Looking at amp hours on paper I'd get
around 33 hours of operating (calculations here

<https://docs.google.com/spreadsheets/d/1iMoxFaz4LxE1N9BUUOBxKgtoME8QLftqJYUnBnnUv7s/edit?usp=sharing>)
though I imagine there'd be quite a voltage drop by the end of
that, but even half that operating time would be pretty good.

Thoughts? I don't have time to set up a rechargeable option
really.



--
--
Simon Rumble <simon@... <mailto:simon@...>>
www.simonrumble.com <http://www.simonrumble.com>
VK2VSR
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...

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