¿ªÔÆÌåÓý

Date

Re: Calibration - my approach #ubitx

 

The technique using WWV is more than good enough if you keep one thing in mind.

The mater osc referenced to the crystal osc is the source for the HFOm IFLO and BFO
so they all move if the master OSC? moves.

IF you do the cal you may have to move the other two to have it all line up.? however
In my heart 30hz is not a significant error.? Must have been awful for those guys using?
old school VFOs with dials calibrated to 1khz.? ;)? ? Then again I manage to talk to people
with my Tempo-one (old school analog tube).

I use a crystal source (20mhz) that's dialed into WWV 30 years ago and checked as
a very accurate source.? That is all and then go through the process.

I do it on receive. just as accurate ans the RX and tX should be the same.

For 20MHz source, set RX for 1khz tone (20.001 or 19.999 depending on selected sideband).
Use counter to measure tone out of the RX (1000.0 hz).? For the 5351 based systems I set the?
correction for the crystal osc by measuring the the its highest frequency output first with a
counter and make that correction as others have noted.? Then I only need to touch up the BFO
so its at the right point on the filter slope. at that point if there is error if the control has the
option I correct the IF offset.? Over all I do it 2 or three times for high accuracy or call it good
enough.? Usually if its it is within about 10hz or less and that better than most radios out there
I stop there.

For frequency stability its all tied to the 25mhz osc and that is usually 20 or 50ppm part?
over the temperature range so over time It drifts a few Hz to aging and the rest is
temperature.? For room temp plus or minus less than 10C change its a small error
and a generally reproducable one.

Allison


Re: share your BITX success stories

 

My wife had watched me carefully collecting (inexpensive) parts to build a uBitX over many months. When she heard about Ash¡¯s ¡®elves are busy¡¯ post,she game me the $$$ to buy one. It¡¯s been fun, and I¡¯m planning to try it on FT8 tonight (finished soldering the cables a couple nights ago). It¡¯s exactly what Ashhar designed: an amazingly inexpensive transceiver that, with a little work, will soon do almost everything my FT-817 can - with a better receiver! It¡¯s cheap, it¡¯s fun, and I¡¯ve learned a lot from it and from the others on this list.


Re: Looking for a single row 16pin ribbon cable source #parts

 

I have bought this one:



or look for hdd cables and use one row only as others are suggesting.


73 Leopold S52UF


Re: A friendly suggestion for Farhan.

 

I seem to have missed this simple capacitor replacement for more power hack. Is there a chart of higher power at higher frequencies? Other boards have solutions of using different finals and some other parts to get more reasonable power out across the range of use. And other mods with a cheap and noisy amplifier kit to bypass it's shortcomings. All these alternatives, and simple performance hacks for "audio pop, keying, etc." are not beyond my current abilities, but excessive when added all together after the initial expense. Can anyone point me to a post about this capacitor thing? And the spirit of QRP is not wasted on me. But do you think this point of the solar cycle is a good time to be using very low power anywhere on the bands? Some people are just now getting into Amateur Radio on a restrictive budget. I spent my radio money on medical accident bills while taking a class for my General Licence and was introduced to the BITX 40. The hardest part was coping with some of the personalities found in this group. And found I like Radio Electronics more than making contacts just for the numbers. Rag chews about hardware are great. Suburban noise and obstructions, not so great.


Re: Why I bought a uBITX

Laurence Oberman
 

Indeed

I have always said folks need to be more appreciative of what they are
getting here and less ready to bicker/moan about stuff.
Its an awesome little radio and provides freedom for those who want it
and simple function for those who just want it to work.
This group of folks is awesome and will help with any issues so is
pretty much the best of both worlds.

Thank you again Mr Fahran
73 KB1HKO
Laurence



On Wed, May 16, 2018 at 11:52 AM, R. E. Klaus via Groups.Io
<reklaus@...> wrote:
First, Mr. Farhan, thank you for developing the BITX series of radios. I
think there has been a great need for an inexpensive HF radio particularly
for the QRP operator. I have a couple (used) QRO rigs but have a desire to
try QRP and portable operation. I would like to have a FT-817 but they are
way beyond my budget. When I heard about the uBITX, I had to check it out
and bought one ( now I am looking for the "perfect" (for me) case.) The
basic uBITX is a good little radio. My wish list would be to have 10 watts
PEP from 80 through 10 meters (many fixes available) and for it to have some
type of output indicator to help avoid over driving the output and
distortion. May be a very basic CAT interface to use a tablet for digital
modes.
Now a suggestion to the group originator. I find it interesting that the
highest number of posts seem to involve bickering over the best software
developer/development. Maybe it is time to split the group into separate
groups one for software developers and one for basic usage and
modifications.
Roxie -- K1AUS


Re: Why I bought a uBITX

 

¿ªÔÆÌåÓý

I was with you until the split¡­

The world is full of split¡­.

In this case, I don¡¯t see how you can split the software, from the hardware as there is no blurry line, no sharp distinct line between the two¡­..they are the same animal¡­.they are both components of the radio, and they do not work exclusively from each other in vacuums¡­¡­but work side by side, interwoven¡­..and attempts to break the software discussions out and make them separate¡­.with such justifications as¡­..the software compatibility with the IDE the user chooses and whether something else exists at some level or not¡­..is not exclusive from hardware mods that are required to make some of the software versions and flavors work¡­.or enhance them¡­you want to miss out on that?

As a systems guy¡­..who appreciated that my job existed because there were users, not the other way around¡­.and that I had to create a system that worked for everyone¡­..

How about a shift in thinking??

What about thinking more about how to make it work for everyone, (let me tell you, with my experience, this environment is really hard to stomach sometimes, I would love to make it work better, but, then that would be better for me? right? what about you?)

And I bet you know what is the natural progression that comes next? right? If you would like something separate, just like if you would like something separate in the software¡­.start working on it.

As clumsy as one big dump is¡­¡­that is desirable¡­..the thing that is missing is easy retrieval¡­..the tools for that exist, but the biggest problem is compliance from hundreds of ¡®right¡¯ ideas¡­.expectations cause work¡­..who wants that?

Craig?
KM4YEC



On May 16, 2018, at 11:52 AM, R. E. Klaus via Groups.Io <reklaus@...> wrote:

? First, Mr. Farhan, thank you for developing the BITX series of radios. I think there has been a great need for an inexpensive HF radio particularly for the QRP operator. I have a couple (used) QRO rigs but have a desire to try QRP and portable operation.? I would like to have a FT-817 but they are way beyond my budget. When I heard about the uBITX, I had to check it out and bought one ( now I am looking for the "perfect" (for me) case.) The basic uBITX is a good little radio. My wish list would be to have 10 watts PEP from 80 through 10 meters (many fixes available) and for it to have some type of output indicator to help avoid over driving the output and distortion.? May be a very basic CAT interface to use a tablet for digital modes.
? Now a suggestion to the group originator. I find it interesting that the highest number of posts seem to involve bickering over the best software developer/development. Maybe it is time to split the group into separate groups one for software developers and one for basic usage and modifications.
Roxie -- K1AUS


Re: A friendly suggestion for Farhan.

 

Hi Gordon,

I've been down the power path.? As a very active VHF/UHF op I have power to the 350W region?
from HB amps.? Its a lot of "drillin and blastin" goes into making them.? I have 4 HB radio for
6M alone plus 2m and 432 transverter to a 10M HB as I like to do weak signal SSB work.?

However when I turn on the HF side...
I have five commercial picks a restored Tempo-One for when I need to dip a plate.? Then my?
three TenTecs (Triton at 100W, Argonaut 5W, Eagle 100W) and the orphan the FT817.? What
do I turn on most often, It varies between the HB 20m, KD1JV Slopbucket 20m, the 10M HB
and then the Argonaut usually on 40M.? ?There are others I use less often like the 1W 40M rig,
and KNQ7A 40M radio.

I've spent the last few months catching up on projects for myself and helping? other local club
members with their uBitx.? Now I get to build mine for real rather than the protoboards I did
over three years ago during the minima/ubitx development days.? The package will be
unique, mini manpack style.

FYI the easy way for a tuner is make one, there are a bunch of kits and designs to copy.? If
you want an auto tuner the Elecraft T1 is both good and compact enough to reformat into
a radios box.? Its limit is 10W (20 peak).?

Usually I cheat and use a half wave end fed for 40/20/10 (PAR/LNR EF40/20/10) as it works
and with additional ?cut and pre-tuned wires I can cover 15M and 17M.? For less than
8 ounces it saves carrying or needing a tuner and it avoids the losses of a tuner.? At home
I use the LND EF-QUAD which is resonant at 40/20/15/10.??

The biggest issue was free time, retired now and remarkably its worse than working!


Allison


Re: share your BITX success stories

Bo Barry
 

Agreed! ?I'm still struggling getting audio levels right. It's hard to turn my nearby icom 7300 down low enough to see a clean signal.
On FT8 soon
Bo W4GHV since '54


Re: uBitx Opto Coupler / VFO not working #ubitx-help #ubitx

 

I thought the same, I even checkd the polarity with a battery just to make sure.
Yes the encoder pins are OK.


share your BITX success stories

 

With all the mud in the water these past few days, I figured I would share something positive.? Lately I've been playing with FT8 on my ?BITX.? I am more interested in learning as much as I can about propagation and antenna optimization than talking to strangers most of the time.? Say what you want about digital modes, they meet that requirement for me.? Last night I completed a QSO with an operator in Russia 4582 miles away on 30m putting out 4.67 watts (as measured with my QRPguys dummy load/power meter).? Sure I just missed the illustrious 1000mi/w but it is a personal ?BITX best for me not counting WSPR which even though is only a one way mode continues to amaze me.

Let's lighten up the mood in this joint.? Share some good stories.

--


Re: Laptop power supply #ubitx

 

I found that wrapping the interfering ps with aluminum foil (in case ground it) solves most of it.
Il 16/mag/2018 03:29, "Lee" <mr.olson@...> ha scritto:
>
> Just bought a 12 volt 5 amp laptop type power supply from eBay for $6.64.? I have read that some could interfere with our radios.?? I wanted to shorten the 12v cable.? I just hate too long or messy wrapped up cables. I thought I would cut through the plastic lump and remove the ferrite choke and put it closer to the power supply and then put some heat shrink around it.? To my surprise there was not any ferrite inside that blob of plastic.? I had some snap-on ferrite chokes and used one of them.? It seems to be working fine.? I wish I would have tried before shortening it.? So if you have a noisy power supply give a snap-on choke a try.
> --
> ????? Lee - N9LO
>
> ????
> "I Void Warranties"
>


Re: Laptop power supply #ubitx

 

I use industrial closed frame power supplies as they can be had cheap.? However
very few are quiet in the raw.? My solution is a aluminum diecast box with CORCOM
filtered line input with added help?and well filtered output.? KA7EOI has the filter
part of the solution.

The brick on a rope? (laptop) power supplies I treat with clamp on ferrite as needed?
neat the brick.? Usually two of the larger core ferrites on both sides do it.? Note large
core clampon are used so I can do a loop though so that the wire passes through twice
and its much more effective.

Many LCD of they use a brick on a rope need silence treatment (ferrite).? Or try another.
it can also be the source and the computer it self is the source and the LCD cable
is the antenna radiating it!? Again choke the cables...all of them.

Its important to note that a radio in a shielded(screened) box with coax feed should
have less issues but if the feed is not properly choked you can have noise on the shield?
and that will couple to the antenna and you hear it.? ?So choking the coax is important
so you don't bring noise to the antenna.

My shack is isolated from the power line and run off battery/solar system sufficient to
run 100W radios.? It was part of the hobby (experimenting with solar power) and?
a solution to noisy power line powered gear.? Ferrite, yes a lot of it in use.? For
those pesky wall warts I use the end of an extension with chokes inserted and
then a three wire plug to isolate the wart from the house grid.

Allison


Re: Should we adopt the KD8CEC firmware?

 

Arv

I have to say this is the best post on this subject in quite some time.
It certainly seems that the original firmware could use some
improvement/updating. Does it need all the additional features in Ians
code? I don't know, maybe Ashhar and Ian can work that out and strike a
happy medium.

Art N4EZZ <n4ezz@...>
GnuPG key ID 0x6712DD0E
=============================
there's no logic behind anything that happens here

On 05/16/2018 09:57 AM, Arv Evans wrote:
Interesting that this single subject has generated more comments than any
other topic.
Some comments are on-topic (*Should we adopt the KD8CEC firmware?*) while
others
seem to have drifted off into discussions of coding styles, coding
strategy, and which
functions should be supported in the factory software load. All points
have some validity
as suggestions for personalization of your own uBITX, and will probably be
considered
when Farhan writes and installs firmware for future BITX designs.

My own opinion (for whatever that is worth...?), is that the factory
software needs to insure
that the rig is fully operational, and that enough functionality is
included to make the
transceiver useful to those who are not interested in writing or modifying
code. Beyond that
it is up to the owner if she or he wants to make changes to hardware or
software. How those
changes are organized, designed, and installed is then up to each
individual owner. That
is a personal issue, and not a global one.

If you are going to modify existing firmware or are going to write your own
firmware, then
what is in the factory code is not an issue because you are going to
replace it anyway.
This sort of denigrates these person's comments regarding what the factory
firmware
should or should not include.

Has this topic evolved in enough different directions that we need new and
more specific
topics started for each issue (BITX coding methods, BITX firmware
functions, BITX code
writing for beginners, BITX firmware testing and quality control, BITX
alternative processor
systems, BITX CAT control, etc., etc.)?

Arv K7HKL
_._


Re: A friendly suggestion for Farhan.

Gordon Gibby
 

¿ªÔÆÌåÓý

"If your inclined look in the files area of this forum under KB1GMX, there are two files called?
HF-use-Fet 1 and 2.? Its fairly simple and if built well its a solid amp.? Pay attention to the?
mechanical build.? Its a 1-2 watts in for more than 40-50 out amp for all HF using two IRF510s.?"


Always enjoy your comments, Allison.? ?For me, to get the thing to eventually make 10 watts out, maybe a bit more on lower bands, is plenty.? We're going to use this as a ARES club project in about 2 months and by then I'll have sorted out the newer software.? ?The original Ashar Farhan software worked fine for all except for the frequency acceleration.? ?I made a little tweak here or there to allow me to skip between bands as I recall, and i think I adjusted the constants in the cw tuning abit.??

?


It has been a fine rig for the tiny amount of time I've been able to donate to it.? ?I have about 3 BITX40's one or two waiting on me, and a SB-102 needing work on an oscillator stage also, and a 2nd uBitx waiting to be installed somewhere......but with the little time I've had it worked to make WINLINK conenctions to several states and that was plenty good enough for me.? ??


When I get some "free time" I'm going to make some of the simple driver and final amplifier adjustments y'all have been working on and possibly try Ian's software also since everyone raves about it.? ? Just haven't been able to work on that with so many other things happening in Emergency Communications land.?


Really enjoy the RF discussions on this group.? Learn a LOT from all of you,

cheers,

gordon





From: [email protected] <[email protected]> on behalf of ajparent1/KB1GMX <kb1gmx@...>
Sent: Wednesday, May 16, 2018 11:30 AM
To: [email protected]
Subject: Re: [BITX20] A friendly suggestion for Farhan.
?
One possible solution for those that want power....
Whats funny is I have built many QRP radios, I mean something over 10 of them all SSB.
Generally if the 3-5W didn't do iItt then 100 might have.? At one point I decided an amp
was a solution so I built it and it works well, though rarely use it.? Why, I find I make
contacts at?lower power and when I cannot 100W isn't enough.??

One thing building an amp that works and doesn't fry everytime you look at it is on face trivial.
At the same time its about as non trivial as one can get.? A good amp is a mechanical project
as you are managing heat and sometimes much more than guessed.

The next possible increment up is not 20W:
If your inclined look in the files area of this forum under KB1GMX, there are two files called
HF-use-Fet 1 and 2.? Its fairly simple and if built well its a solid amp.? Pay attention to the
mechanical build.? Its a 1-2 watts in for more than 40-50 out amp for all HF using two IRF510s.
I didn't design it but I can say that if you build it soldering and mechanical construction has
to be 100% and there are the tribal tricks not written up that need to be known.? An aside if
you cannot cut aluminum pieces and drill and tap holes your already on the short side?
skills required.? ?To farm out machine shop work is expensive even in bulk.

The path to 100W is not cheap:
The better transistors path.? RD16HHF 4.75$ each from RF parts.? Its a 12V 20W device and
K5BCQ has gotten as much as can be done with those(20W near flat from 160 to 6).? The
next step up?is RF70HHF or 2SC2879 both types you need a pair (about 60$us) and do
about 100W and after all the other parts and materials expect to spend about 150$ or
more plus all the mechanical work required.? A pair of tubes can do this easy and then?
your looking for 900V power supply and high voltage components with the safety? risks.

My suggestion, likely the less expensive route:
Build a better antenna.? Less expensive and you will hear stations better.? Use a full size
dipole at least a half wave length high (or higher) for example 20M for the 40M band.? ?A
wire beam for 20M?can be a considerable equalizer.? A bit of wood, wire and rope.? I happen
to like the VE7CA tribander (20/15/10M).? ?A wire beam for 40m is not out of the question,
the group I hang with does both of those for field day.


Allison



Re: Laptop power supply #ubitx

Daniel Conklin
 

Some are worse than others.? The power supply for my laptop raises the noise level 1.5 S units on all the HF bands, but the one on my HD monitor completely wipes out the 20 meter band and no others.? The 12V 30A switching supply I was using for most of my equipment put out spikes every 70 KHZ on 40 meters and 15 meters, but was fairly clean everywhere else.? I could clearly see the interference using an SDR Play. I tried the ferrite? chokes with minimal success.? I found the information in this website to be helpful:?

Dan, W2DLC


Re: A friendly suggestion for Farhan.

 

I second that and? of course a built-in tuner would be nice too!


rOn

On May 16, 2018 at 11:56 AM atouk <atouk@...> wrote:

Maybe the next logical step is to convince Ashhar that instead of a new radio, his next offering should be the uBitAMP.


On 5/16/2018 11:51 AM, Ralph Mowery wrote:
There seems to be many amplifiers on ebay that put out about 70 watts for around $ 25 to $ 50.? Those are just circuit boards with parts mounted or kits. No filtering that you would have to add and a TX/RX switch and box to put it in. Going much about 10 watts would seem to knock it out of the portable weight limit .? I was talking with some friends on 80 meters this morning and using the 16 watts I get out (after the transistor mods) to drive a Drake L4B amp to somewhat over 150 watts out and getting good reports.

I am glad this rig is on the market as is.? Gives me a chance to make some modifications and my main goal is to use it with some transverters that need about 5 to 15 watts of drive depending on which one I use.

I am not much for designing things, but do enjoy playing around with others ideas.

de KU4PT


On Wed, May 16, 2018 at 11:30 AM, ajparent1/KB1GMX <kb1gmx@...> wrote:
One possible solution for those that want power....
Whats funny is I have built many QRP radios, I mean something over 10 of them all SSB.
Generally if the 3-5W didn't do it then 100 might have.? At one point I decided an amp
was a solution so I built it and it works well, though rarely use it.? Why, I find I make
contacts at?lower power and when I cannot 100W isn't enough.??

One thing building an amp that works and doesn't fry everytime you look at it is on face trivial.
At the same time its about as non trivial as one can get.? A good amp is a mechanical project
as you are managing heat and sometimes much more than guessed.

The next possible increment up is not 20W:
If your inclined look in the files area of this forum under KB1GMX, there are two files called
HF-use-Fet 1 and 2.? Its fairly simple and if built well its a solid amp.? Pay attention to the
mechanical build.? Its a 1-2 watts in for more than 40-50 out amp for all HF using two IRF510s.
I didn't design it but I can say that if you build it soldering and mechanical construction has
to be 100% and there are the tribal tricks not written up that need to be known.? An aside if
you cannot cut aluminum pieces and drill and tap holes your already on the short side?
skills required.? ?To farm out machine shop work is expensive even in bulk.

The path to 100W is not cheap:
_._,_



?


Re: Calibration - my approach #ubitx

 

Does anyone have a simple way to calibrate the uBITX when a good service monitor is at hand ???

I know the unit will not be super stable and don't expect it to be.? I have a service monitor that I know is accurate to less than 1 HZ at 10 MHz. Every time I try to get the ubitx set I wind up messing up the calibration, and have to start back from a loaded set of parameters.? I have it working fine now, but not too sure how accurate it is set.? I usually feed a 1 khz tone into the mic and read the frequency on the counter to see if it is that far above or below the ubitx LCD.?



On Wed, May 16, 2018 at 10:29 AM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
The calibration factor adjusts the nomially 875000000 value for si5351bx_vcoa down in ubitx_si5351.ino
in Farhan's stock ubitx code.
Any change to vcoa? (which is the frequency of the VCO inside the si5351 in Hz, nominally 875mhz)
is exactly proportional to the change you can expect in the operating frequency of the rig.

So if you are receiving a 10mhz WWV signal and find that your radio dial reads 10000030 when at zero beat,
then reduce vcoa by? ?875000000*(30/10000000) = 2625

With that, your rig should be exactly on frequency for anything from 500khz to 30mhz.
One of the joys of having all oscillators being based on a single 25mhz reference crystal.




Re: Should we adopt the KD8CEC firmware?

 

Interesting that this single subject has generated more comments than any other topic.?
Some comments are on-topic (Should we adopt the KD8CEC firmware?) while others
seem to have drifted off into discussions of coding styles, coding strategy,? and which
functions should be supported in the factory software load.? All points have some validity
as suggestions for personalization of your own uBITX, and will probably be considered
when Farhan writes and installs firmware for future BITX designs.

My own opinion (for whatever that is worth...?), is that the factory software needs to insure
that the rig is fully operational, and that enough functionality is included to make the
transceiver useful to those who are not interested in writing or modifying code.? Beyond that
it is up to the owner if she or he wants to make changes to hardware or software.? How those
changes are organized, designed, and installed is then up to each individual owner.? That
is a personal issue, and not a global one.?

If you are going to modify existing firmware or are going to write your own firmware, then
what is in the factory code is not an issue because you are going to replace it anyway.?
This sort of denigrates these person's comments regarding what the factory firmware
should or should not include.

Has this topic evolved in enough different directions that we need new and more specific
topics started for each issue (BITX coding methods, BITX firmware functions, BITX code
writing for beginners, BITX firmware testing and quality control, BITX alternative processor
systems, BITX CAT control, etc., etc.)?

Arv? K7HKL
_._


On Wed, May 16, 2018 at 9:11 AM, Tim Gorman <tgorman2@...> wrote:
On Wed, 16 May 2018 01:14:34 -0400
"D. Daniel McGlothin KB3MUN" <kb3mun@...> wrote:

>
>
> No, I don't care whose software you choose to extend.? Or whether you
> write your own from scratch.

Then why did you say: "As to the "CW support for TUNE" issue being
discussed, in circumstances like this, I would simply make the
conditonal compilation guides make the dependency clear--so no real
bother at all:"

How will this make my software work with other software that doesn't
have conditional compiles?

>
> It doesn't matter to me, or even to you, as once one chooses to
> change the uBITX software, whatever is factory loaded is erased and
> over-written by your selected software modified by whatever changes
> you choose to make to that selected software.

Then you are not understanding the fact that you either have to take
into consideration *all* possibilities that can be generated from
software with conditional compiles in order to keep your modifications
workable in all cases or you have to duplicate all needed functionality
in your own software.

If the standard load becomes a load that is full of conditional
compiles and is so complicated that it is difficult to even add a menu
item then it *does* matter what the factor load is.






> This seems to be the point that others are making for you too. You do
> not have to base your software modifications on any particular source
> of software.

Sure I do. If I have to take conditional compiles into consideration
for one particular source but I don't have to take conditional compiles
into consideration in a different source then I *have* been forced to
base my software of the particular source I choose to modify.


>? Once you make the decision to make the uBITX software
> load different from the factory load, you accept all responsibility
> for what you load into your radio, even if you choose to load an
> unmodified software build from anyone, even if that is a copy of the
> source code for the factory loaded firmware.

But if I am trying to make a useful contribution to the community at
large then I want to minimize the number of different options I have to
code for.

>
> So use those software systems you know (and approve) of as the basis
> for your changes.? You make the changes; you support the changes you
> make to the software that you load to your radio.

That's what I'm going to do. But if I only code for my own use and
everyone else does the same then how does the community at large
progress?

> In any case, I'll be happy to assist with software questions (from a
> 30+ year programming perspective), should you wish.? But I've no need
> to argue for a viewpoint you reject.
>
> Daniel KB3MUN
>

The only viewpoint that I reject is that the ubitx should become a
retail offering where you have to be at least a coder of intermediate
capability to play with the software.

For once the simple software load is abandoned its upkeep *will* be
abandoned as well. That's just how things work.

tim ab0wr





Re: Laptop power supply #ubitx

 

I used a powersupply similar to yours that came with a chinese CCTV system also provides 12V/5A.
So far haven't had problems with noise generated by the powersupply.

John


Re: A friendly suggestion for Farhan.

 

¿ªÔÆÌåÓý

Maybe the next logical step is to convince Ashhar that instead of a new radio, his next offering should be the uBitAMP.


On 5/16/2018 11:51 AM, Ralph Mowery wrote:

There seems to be many amplifiers on ebay that put out about 70 watts for around $ 25 to $ 50.? Those are just circuit boards with parts mounted or kits. No filtering that you would have to add and a TX/RX switch and box to put it in. Going much about 10 watts would seem to knock it out of the portable weight limit .? I was talking with some friends on 80 meters this morning and using the 16 watts I get out (after the transistor mods) to drive a Drake L4B amp to somewhat over 150 watts out and getting good reports.

I am glad this rig is on the market as is.? Gives me a chance to make some modifications and my main goal is to use it with some transverters that need about 5 to 15 watts of drive depending on which one I use.

I am not much for designing things, but do enjoy playing around with others ideas.

de KU4PT


On Wed, May 16, 2018 at 11:30 AM, ajparent1/KB1GMX <kb1gmx@...> wrote:
One possible solution for those that want power....
Whats funny is I have built many QRP radios, I mean something over 10 of them all SSB.
Generally if the 3-5W didn't do it then 100 might have.? At one point I decided an amp
was a solution so I built it and it works well, though rarely use it.? Why, I find I make
contacts at?lower power and when I cannot 100W isn't enough.??

One thing building an amp that works and doesn't fry everytime you look at it is on face trivial.
At the same time its about as non trivial as one can get.? A good amp is a mechanical project
as you are managing heat and sometimes much more than guessed.

The next possible increment up is not 20W:
If your inclined look in the files area of this forum under KB1GMX, there are two files called
HF-use-Fet 1 and 2.? Its fairly simple and if built well its a solid amp.? Pay attention to the
mechanical build.? Its a 1-2 watts in for more than 40-50 out amp for all HF using two IRF510s.
I didn't design it but I can say that if you build it soldering and mechanical construction has
to be 100% and there are the tribal tricks not written up that need to be known.? An aside if
you cannot cut aluminum pieces and drill and tap holes your already on the short side?
skills required.? ?To farm out machine shop work is expensive even in bulk.

The path to 100W is not cheap:
_._,_