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Date

Re: Simple spur fix

Warren Allgyer
 

My implementation of the filter with a single transformer. I encapsulated the transformer and the filter with heat shrink and mounted it as a single component. As before the power levels are standardized to approximately 2 watts for easy comparison.

A capacitor is indeed needed between the low impedance transformer output and the center tap of the mixer transformer. I soldered a 0.1 uF SMD, one side to the output pad of R27 and the other side served as a connection for the transformer low impedance output.

The filter input is attached directly to the other R27 pad. I elected to not use a second transformer because the source is much closer to the filter impedance than it is to 50 ohms.

In my case the transformer does not dramatically reduce the spurs versus the bare filter. The primary effect, and one that is desirable, is that a much more reasonable audio drive level can be used. These traces were made using a 1 KHz tone at 30 mVrms, a level that is commonly used as the "high" level for microphone input in commercial transceivers and one that should be easily attained without increasing the gain of the audio input stages. It does, however return the radio to being susceptible to intermodulation distortion because the levels are increased back to closer to the stock configuration.

Maximum power levels are also restored to nearly the same as the unmodified radio...... not a good thing in my view because IMD was unacceptable at any SSB power level above about 1.5 watts in the original. I suspect that is the same with the transformer added but it needs to be verified. Also needing verification is the SSB passband. According to tests on the filter it should be much more flat with the transformer added.


WA8TOD



Re: Surprised by generous and kind act #bitx40

 

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Total agreement here.? Amateur radio - elmering, helping each other out, and so on - there used to be a code of conduct, which is a good thing. ? I think it's still published and in the handbook, but I rarely hear anyone mention it.

On 09/10/2018 06:02 AM, David Wilcox via Groups.Io wrote:

This is TRUE ham radio.

Dave K8WPE

On Sep 9, 2018, at 12:15 AM, Robert D. Bowers <n4fbz@...> wrote:

Today I was greatly and pleasantly surprised.? I'd mentioned that I was thinking about converting my BITX20 to 40 meters, and I'd related some stories of frustration with the local ham community (generosity and willingness to help others seems to be a rarity in this area).

When I got our mail, there was a package in it - with a BITX40!? The housing it was in is very attractive as far as my wife and I are concerned - and perfect for our car.? The neat part was that you could see the circuitry in it - and the case also would lend itself to portable operation!

I won't embarrass the sender, but I will say it came from another state.? For many years, I've insisted that there was no such thing as Karma... but this suggests otherwise!

To the sender (not named) - a big Thank you! from both of us, and (laugh) no worry about "paying forward" - we do things all the time like that, whenever we can (we may not have much money, but we do have skills and knowledge we share).? Generosity and helping others is not a big price for gifts like this - in our opinion!


Re: install 20x4 I2C Display - Problem without 3.3v ?

 

Fabian,

I am not familiar with your particular display or the CEC software.
Perhaps someone else can respond here after looking at the photo of your display
in your previous post, and tell you if it will work with the CEC software in parallel mode.
?
You should be able to determine if the pullup resistors for the SDA and SCL pins
are present by using an ohmmeter.? Measure from the SDA pin to the 5v power pin.
If the resistor is present, it will be between 5000 and 2000 ohms.? (If there is no resistor
present then that reading will likely be 50000 ohms or more.)? You can then find that resistor
so you can remove it by measuring from the SDA pin to the various possible resistors
and looking for zero ohms.? Then do the same for the SCL pin.

For the CEC software to be able to talk to the i2c adapter board, you must make sure
the software knows the correct i2c address to use as per post?/g/BITX20/message/39966
The easiest thing is to scan the i2c device by running special i2c scanning software on the Nano.

Also, the i2c adapter board must be using a particular interface IC that the CEC software
knows how to talk to.? I believe that should be either a?PCF8574T or?PCF8574AT

Jerry


On Mon, Sep 10, 2018 at 08:09 AM, sdr freak wrote:
Hello Jerry!

Very much thanks and that is nice to hear these kind of post, i looking forward now and every post like this, which gives me good information is very nice!

ok when put the I2C board away from the display, with desoldering of this part, then i can post you few pics from the backside of the I2C board and i can run for first time my ubitx with the CEC software at the 20x04 Display in paralell-mode ? or is there a new problem to use it, when i desolder the I2C board awy from the Display and would run up like an normal paralell 20x04 Display? is there anything what i should or must do in progress of use as paralell Display, like other mods or something or is that ready to use at this point?


Re: Simple spur fix

 

Kees noted that you can't actually ground through C11 but rather R13- despite of my attempt to. :)
I'll switch that up this evening.

John
KC9OJV


Re: More PA Putzing ..

 

On Sun, Sep 9, 2018 at 04:02 PM, jim wrote:
id Change the output transformer (T11) to 2 FB43-801's like a binoc core ..3 T pri, 5 T sec ..just to start ..The other one was kinda making the waveshape look like a triangle wave generator (lotsa 3x harmonics I assume)
Sounds like drive issues and not enough current.? Also 3:5 Turns may be a bit steep try 3:4 or 2:3.

Don't forget you have the fets standing on those long legs at at low impedance loads
those legs are simple low value chokes.? Doesn't help that the heat sinks are antennas
near the driver and predriver.

Allison


Re: install 20x4 I2C Display - Problem without 3.3v ?

 

Hello Jerry!

Very much thanks and that is nice to hear these kind of post, i looking forward now and every post like this, which gives me good information is very nice!

ok when put the I2C board away from the display, with desoldering of this part, then i can post you few pics from the backside of the I2C board and i can run for first time my ubitx with the CEC software at the 20x04 Display in paralell-mode ? or is there a new problem to use it, when i desolder the I2C board awy from the Display and would run up like an normal paralell 20x04 Display? is there anything what i should or must do in progress of use as paralell Display, like other mods or something or is that ready to use at this point?


Re: More PA Putzing ..

 

Just one step at a time ....Did replace R97 and R98 (47 ohm) on the mosfets gates with 10K resistors ...Improved drive and output?

And likely more instability.? Your getting more because the drivers cant so your making what little you get available to the MOSFET.

Solution is not, symptom is lack of drive available.? Work backward, assume irf510 does 13db of gain (power factor of 20).
IF you want 10W out you REQUIRE .5W in.? If you do not get that, low power.

Allison


Re: K5BCQ uBITX Relay Switched LPF/BPF board

 

Skip,

I revised the board to add a 9th relay as shown in the picture.

73 Kees K5BCQ


Re: Antenna Loops #off_topic

 

If you have room enough I would look to reasonably efficient wire antennas such as a G5RV, Doublet and I have seen a very cheap new small tuner from MFJ, don't remember the exact model, I think it is prices at 50Usd.


Il 09/set/2018 16:29, "David Posthuma" <davep@...> ha scritto:
There have been many posts regarding end fed?antennas. I hope these posts were helpful.?

My favorite portable antenna are?various loops, either full-wave?loops,?quads, or Miniature Magnetic Loop Antennas. Why do I like loops:

  1. Because they are a closed circuit resulting in very low noise, far less than a dipole, verticle, or end-fed wire (NOTE: You can't work what you can't hear)
  2. Because the can be polarized vertically for low-angle radiation, horizontally, or even a hybrid of these
  3. Because they are easy to build and match to a 50-ohm coax
But for portable operation, nothing beats a Minature Magnetic Loop antenna. This is because it is light-weight, directional, and can literally sit on the ground and still work perfectly well!

I wrote an article about Miniature Magnetic Loop Antennas for the Elecraft.com team way back in 1999 when they were not yet so popular (i.e., I was a builder of the early K2 and beta tester for the 100 watt?linear). Check it out at?. You can build these antennas with materials from any home improvement store. I hope they inspire some antenna building from among the uBitx?building family.

David Posthuma, WD8PUO


Minature Loop antenna #off_topic

JOHN CRONHELM
 

I have the Wonder wand 750 minature loop antenna. from Radio World uk. Tunes 7mhz to 50mhz. Excellent indoor antenna when propagation good.
John vo1jcc.


Re: 45M Filters

 

On Mon, Sep 10, 2018 at 04:07 AM, Raj vu2zap wrote:
N2CBU
I bought twoToycom-45E2BF from N2CBU and two T45U15BG from another eBay seller, the specifications are slightly different but at least I have selection to choose from. Thanks for figuring this out Raj, now maybe we as a group came move forward again on the uBitx.

Joel
N6ALT


Re: Surprised by generous and kind act #bitx40

 

How about a pic of the 'very attractive' case?


Re: uBitx Antenna #ubitx-help

 

¿ªÔÆÌåÓý

Funny Iso, I also have one that works very well too. Maybe Vince¡¯s SWR meter has had the golden screwdriver inside it. And if he ran a KW into it the diodes might be fried or the load resistors too.?

Skip Davis, NC9O

On Sep 10, 2018, at 07:41, iz oos <and2oosiz2@...> wrote:

I have a cheap CB swr meter (just swr not power meter) and a crossneedle ham-meter. In the instruction sheet they say it is usable between 1.8-30! They are liers!!!!? It works from 1.8 to 50Mhz (yes up to the 6meters band) !!! Very similar reading to the ham meter!!! What a shame... They don't even know what they sell... hihi... hi


Il 10/set/2018 07:40, "Vince Vielhaber" <vev@...> ha scritto:
SWR and Wattmeters made for CB are often worthless in the ham bands, unless you're only using 10M.? I picked up a Firebird SWR/Wattmeter a while back that was supposed to be good for 1.8-30 MHz.? HAR!? That thing won't even read accurately (or even semi-accurately) at 21 MHz and gets progressively worse the lower you go.? It barely responds with almost 1KW going into it at 3.9MHz.? Needless to say it's going back on ebay.? It is fairly accurate on 10 meters, so it probably is on 11 too.

Vince.

On 09/09/2018 03:13 PM, Gordon Gibby wrote:
The only cb ones I have tried on 2 m are the long parallel rod pick up type, they were quite in accurate

For VHF/UHF I use ham products made for the purpose

Cheers

Gordon kx4z
On Sep 9, 2018, at 13:59, Bill Cromwell <wrcromwell@...> wrote:

Hi,

It might start to be a little shaky on the two meter band. And maybe will work there too.

73,

Bill? KU8H

On 09/09/2018 05:37 AM, gonewiththeego@... wrote:
I was thinking about an Albrecht SWR 20 which I can see that is used
only for CB. Do you think it should work for 20/40m band ?

--
bark less - wag more







--
? Michigan VHF Corp.? ?? ?
? ? ? ? ? ? ? ? ? ? ? ? ?




Re: uBitX NANO programming issues

Jack Purdum
 

Hi Jim:

We ran into a similar problem. "Raw" EEPROM on a "real" Nano (and most clones) is initialized to 0xFF for each EEPROM byte. However, you can't always depend on that. Our solution was to initailize EEPROM address 0 with a single-byte "sentinel" value (e.g., 88) and then in setup() read address 0 to see if it equaled the sentinel value. If not, we assumed the EEPROM was "raw" and we proceeded to do our thing. It also makes it very easy to "re-initialized" the EEPROM by simply forcing EEPROM address 0 to 0xFF.

Jack, W8TEE


On Monday, September 10, 2018, 8:42:43 AM EDT, Jim Sheldon <w0eb@...> wrote:


I had gotten a couple of "bug" reports in the earlier W0EB/W2CTX firmware saying some of the values weren't beening saved properly to EEPROM. ?This caused things not to work properly and quickly got a bit frustrating for the user. ?

I tracked this down to the later crop of Chinese NANO clones (even those being sold by Amazon and other big name sellers). ?It seems that the EEPROM's ?were never properly initialied to (I believe) All FFFFFFFF and had random data in them. ?This caused the programming to think that proper data had been stored by another program (CEC) which we tried to be careful not to ruin and it wouldn't save to that location. ?

As soon as this problem was originally discovered (and later forgotten until the perceived bug got reported) one of the TSW team members wrote an initialization routine to initialize a new NANO's EEPROM and should be done prior to installing any uBITX firmware on a new NANO if it isn't a genuine Arduino NANO.

That routine is available for download on the TSW website in the files section and may solve a bunch of controller not working problems. ?It's called: ?W0EB_W2CTX_NANO_EEPROM_Initializer_v1r2.zip and is located in the "Files Section" directory labeled: "Program sketches for the Raduino (modified for I2C displays) or our RadI2Cino Card using a 2 or 4 line I2C LCD display. "

If you run this on a new NANO it won't hurt anything any should initialize the EEPROM properly. ?Don't use it if your CEC program is running properly and you have saved a bunch of items using his "Manager" program as it will destroy your saved data. ?Same goes for the W0EB/W2CTS programs, but on a new NANO it may prevent some subtle things from happening that create problems.

Jim - W0EB

-


Re: Band scan & Spectrum not working with i2c standalone and CEC -Nextion display

 

Marty

Sorry for my belated reply.?
I've been looking for some new topics these days.?I was also a bit busy because I was in charge of new courses.
I think you have a fully equipped Standalone DSP Meter.?
I think you uploaded the firmware which ends in xxxx_NX.Hex.?To detect a signal using I2C, you must use a file ending with xxx_NX_S.Hex.
It is also necessary to verify that the I2C line is properly connected.

If not, please mail me again.

Ian KD8CEC


2018? 9? 7? (?) ?? 11:36, MD via Groups.Io <martyduplissey=[email protected]>?? ??:

I have been having fun with the ubitx v4 using CEC's firmware and nextion display. My problem is I cannot get the bandscan or spectrum screens to work with the i2c standalone dspmeter addon. I have followed Ian's instructions to a t and no spectrum. The dsp screen, cw decode and s meter work great. I have recompiled the firmware source in the memory saving mode and full blown mode. I have redownloaded the hmi and recompiled it multiple times to no success. What could I be doing wrong?
Marty? ?
-
N5KBP


--
Best 73
KD8CEC / Ph.D ian lee
kd8cec@...
(my blog)


Re: uBitx Antenna #ubitx-help

 

I fully agree with Robert 'my experience of using CB meters is if they're the parallel-strip kind (very common), they may loose some sensitivity at the low end. Otherwise, they did a fair to good job checking the SWR, which is a ratio anyway. (At the upper end of the 'usual' spectrum -sometimes TOO sensitive, but I've used them with reasonable accuracy on 6m.)', mine is parallel strip kind, am not sure you can find the exact model on the ebay everyday (I bought it 20yrs ago) I think it could cost around 10usd, not much more.

Il 10/set/2018 14:55, "Tom, wb6b" <wb6b@...> ha scritto:
>
> Is it still an available meter? Is there an eBay/Amazon listing. If you have tested it against a known good SWR meter, I'd like to get one, if it is still at a good price.
>
> Tom, wb6b


Re: uBitx Antenna #ubitx-help

Gordon Gibby
 

¿ªÔÆÌåÓý

Hi Gang, ?I just like to point out that although I only use these at HF, I have been using them for 35 years or more, they work fine! ? There are only a few technology used to measure standing weight ratio in coming years, and the ones for ham radio use the same technology as CB. ?The CB band is very near the 10 m ham band. ?

The parallel transmission line models would be a little less sensitive on 80 meters due to less pick up, the toroid versions probably work just about the same throughout a wide freq frequency limit

And it¡¯s not hard to build your own! There are quite a few kits ?out there ranging from low-power versions to Hi power versions.

SWR is not really magic, most people in radio have to measure it! ??

If you want to test them, you can make up some low inductance resistor is a 50, 100, and 150 ohms, and use them to test some known SWR values. ? Don¡¯t use wirewound resistors of course, and making resistance by using several in parallel decreases inductance

Gordon.?


On Sep 10, 2018, at 08:55, Tom, wb6b <wb6b@...> wrote:

Is it still an available meter? Is there an eBay/Amazon listing. If you have tested it against a known good SWR meter, I'd like to get one, if it is still at a good price.

Tom, wb6b


Re: Simple spur fix

 

¿ªÔÆÌåÓý

Nice adaptation of the second filter Glen.?

Skip Davis, NC9O

On Sep 10, 2018, at 00:38, Glenn <glennp@...> wrote:

approx. install position. R27 would be removed and short wires fitted. Hole was drilled into main board behind this adapter board.? There are two GND through holes, near R25 and to the right near the transformer also which might be useful. This assumes that R27 removal is the final idea.
<uBITX_45MHz_fitting.JPG>


Re: Simple spur fix

 

Yes, it will need a cap! The PCB layout should have one.

Raj

At 10-09-18, you wrote:
If the filterboard replace R27 will not the two turn winding drain the DC bias CW operation to ground. Block capacitor needed?


Re: HELP

 

One possibility is the software may be thinking you are using a paddle. Did you wire up the key with one of the resistors in series or without a resistor? When using a paddle the factory firmware uses resistor values to determine if you are hitting the dot or dash paddle. A straight key should have no resistor.?

Tom, wb6b