Date   
Re: VK4PP uBitx LPF BANK add-on Board

ajparent1/KB1GMX <kb1gmx@...>
 

For any of the low pass fitlers the easy mod is to wire around the whole built in LPG and 
save the losses.  Then put the 3rd party filters between the antenna jack and the board.

All KT1-3 do is contribute loss and consume power.  You can use the three outputs
TX-A, TXB, And TXC with software changes to control the new board or whatever then.

Allison

Re: uBitx Unfiltered

Glenn
 

Allison,  some nice do-able ideas there. I have some 82.2MHz crystal filters here and thought  that they may eliminate the issues above 20MHz? Happy to send you a pair if they help your project.

glenn

----snipped----------------------------------------------------------------------------------------------------

Result then is a decent 80 -17M radio.   Forget anything over 20mhz the filters before
the amp is much more difficult and otehr issues conspire to make it a mess.  We need
V5 to get that.

The plan for mine was a mil style man pack with 80/40/20/10 as primary bands (must have)
low power RX with AGC and 5-10W TX.  As work on ubitx proceeded it was obvious getting
that in the package identified was not going to fit due to added blocks to make it work
and I found the power needs rather high for something I plan to run on battery.

I will have to come up with my own design to fill that need.  I already have a breadboarded
version that needs to be size reduced to fit.  

Allison



On Sun, Sep 2, 2018 at 05:28 AM, ajparent1/KB1GMX wrote:
Result then is a decent 80 -17M radio.   Forget anything over 20mhz the filters before
the amp is much more difficult and otehr issues conspire to make it a mess.  We need
V5 to get that.

The plan for mine was a mil style man pack with 80/40/20/10 as primary bands (must have)
low power RX with AGC and 5-10W TX.  As work on ubitx proceeded it was obvious getting
that in the package identified was not going to fit due to added blocks to make it work
and I found the power needs rather high for something I plan to run on battery.

I will have to come up with my own design to fill that need.  I already have a breadboarded
version that needs to be size reduced to fit.  

Allison

Re: 4.2” Nextion Display

 

Bill:

This is one I used... https://www.amazon.com/gp/product/B015DMOVJA/ref=od_aui_detailpages00?ie=UTF8&psc=1.



David A Posthuma, WD8PUO
1 (616) 283-7703

-----Original Message-----
From: BITX20@groups.io <BITX20@groups.io> On Behalf Of Bill Robbins
Sent: Saturday, September 01, 2018 5:59 PM
To: BITX20@groups.io
Subject: [BITX20] 4.2” Nextion Display

Can someone give me a link for the best 4.2" display and associated products?

Bill

Re: uBitx Unfiltered

Glenn
 

These are the filters. I haven't swept them but imagine they are relatively narrow 'fm' filters.

Before anybody asks, they are no longer available from www.rockby.com.au 

glenn

Re: uBitx Unfiltered

jim
 


On Saturday, September 1, 2018, 3:41:13 PM PDT, Glenn <glennp@...> wrote:


Appros of nothing, but not to start a new thread ...My current mods and results

Summary: replace T11 and change bias on Q90....appears Q911-912 need help too

Jim

Re: KARMA and BITX

Dexter N Muir
 

I'm sure our Indian folks will back me: I'm sure 'Karma' here should be 'Kudos'. Karma is the 'therefore that' result of 'because this' - the immutable eternal Logic.

73 de ZL2DEX

Re: uBitx Unfiltered

ajparent1/KB1GMX <kb1gmx@...>
 

Glenn,

Use them in good health.  Note 3904s have gain of maybe 3 at 82.2 so you have
to rebuild the 45mhz amp completely.  Also layout at 82mhz is getting fussier than
at 45mhz.

Changing the filter will not cure the output from the power amp getting into the
wide open 45/82.2mhz amp and contributing spurs though I may move them
around.

Also the HFO (osc-3) has to go from 85mhz to 115 mhz and that meas you
exceed the SI5351 code by 6mhz.

// the output msynth dividers are used to generate 3 independent clocks
// with 1hz resolution to any frequency between 4khz and 109mhz.

They are most like 15khz wide but could be much wider for data use.

I can't use them as I said experiments and mods have reduced mine to a
collection of junk.    

One magik pill.

Allison

Re: uBitx Unfiltered

ajparent1/KB1GMX <kb1gmx@...>
 

What are you using for Q90 and all the other 3904s?

Words would make the posting informative.

Allison

Re: uBitx Unfiltered

Glenn
 

Ok Allison, I was thinking more along the lines of a total rebuild. With the obstacles you mentioned, hopefully overcome.
glenn

Re: uBitx Unfiltered

ajparent1/KB1GMX <kb1gmx@...>
 

Glenn,

Thanks,

If I build I will use other topologies that I know work.

Since I do not lust for continuous tuning an low IF in the 8 to 11mhz range
can do multiband well.  Single conversion is simple and can do all the
desired bands.

A good example is the Atlas210 using a spare 9mhz filter. Likely fewer parts.
Lots of filters and relays.

Allison

Re: Sideband Suppression (receive) #ubitx #ubitx-help

Rich AE4OK
 

Useful tip - I was in the deep end and this helped me get out.

Re: uBitx Unfiltered

Brent Seres/ VE3CUS
 

Thanks Allison 
Not afraid to dig into it, just wondered if there was a simple solution..but after reading all the posts I'm not surprised. I have a bunch of 2n2222 as well, so will hopefully replace those transistors you mentioned in your earlier post.
Thanks again

Brent

Re: uBitx Unfiltered

Mark M
 

On 9/1/18 2:58 PM, ajparent1/KB1GMX wrote:
...
IF you using external filters. disable Kt1-3 and run a coax from power
amp to K3. Use external filters.
...

Just to be clear, that means run a coax from pin 5 of T11 to pin 16 of K3, and cutting the trace from T11/pin 5 to KT1/pin 12 (referring to the V3 schematic). Also cutting or removing the existing trace from K3/pin 16 to KT1/pin 5 and cutting the traces for TX A/B/C from the Raduino (perhaps use them to switch the external filters). Is that correct?

I have a set of QRP Labs LFPs for the bands I'm interested in and the matching relay board that I'm planning to use. Haven't decided on the switching scheme yet.

Mark AA7TA

Highest quality uBitx Case ever!

Adam Goler
 

when in doubt, make it out of cardboard. 

Re: uBitx Unfiltered

Jerry Gaffke
 

Easy enough to get the si5351 to hit 115mhz.

One possibility, just run the vco at 920mhz instead of 900 mhz,
a wee bit out of spec but will work fine.
No changes to the code other than some constants in the si5351bx code,
must the recalibrate of course.

Alternately, use the second PLL inside the si5351 to 85 to 115mhz out to clk2,
si5351 output divider for clk2 fixed at 6.
Might be possible to do this using the etherkit si5351 library,
or a major hack to the si5351bx routines.
The G0UPL library might also do it, though I believe it is restricted to two outputs.

Jerry, KE7ER


On Sat, Sep 1, 2018 at 03:59 PM, ajparent1/KB1GMX wrote:
Also the HFO (osc-3) has to go from 85mhz to 115 mhz and that meas you
exceed the SI5351 code by 6mhz.

// the output msynth dividers are used to generate 3 independent clocks
// with 1hz resolution to any frequency between 4khz and 109mhz.

Re: uBitx Unfiltered

Glenn
 

Allison, yes the 'traditional' approach has much to recommend it. I'm in the middle of just such a project myself.  9MHz IF etc, single conversion all hf bands.
glenn

Re: ubitx, TX flapping relay...

Adam Goler
 

That did it! Thanks!

On Sun, Aug 26, 2018 at 19:34 Ion Petroianu, VA3NOI <ion.petroianu@...> wrote:
Adam,
The microphone is polarized.
The switch you had received is connected between PTT line and GND and not in series with the microphone.
The microphone is connected between GND and Mic input. On the microphone capsule you can see that one of the pads is connected to the aluminum shell. That pad goes to GND, the other pad to Mic input. 
When you press the switch you should hear the relays engage and see an increase in current consumption. When you speak the current consumption should increase.
Don't forget to have a dummy load or an antenna attached to the Ant connector.

73,
Ion

VA3NOI

--
Adam Goler, PhD
Cell: (425) 985-8700


"Fear is the mind killer."

Re: uBitx Unfiltered

ajparent1/KB1GMX <kb1gmx@...>
 

Brent,
Not afraid to dig into it, just wondered if there was a simple solution..but after reading all the posts I'm not surprised. I have a bunch of 2n2222 as well, so will hopefully replace those transistors you mentioned in your earlier post.
Thanks again

People have been hoping for a magik pill solution for over three months.
Wish there was one.

Allison

Re: Which xmit transistor is blown?

 

Sean,

Occasionally I get power drop and fluctuation and I found it was the power connector. 1-2A is a lot for the
pin contact.. pull the power plug from the board and put it back a couple of times and see..

Raj

At 01/09/2018, you wrote:
I have had periodic issues with the ubitx that led me to believe that my finals (IRF510) were blown, and the radio seemed to work as expected after replacement, so perhaps they were.

I have a question though...is there a good way to tell what has gone out in the xmit power chain? I recently replaced Q90 with an mmbt2222a (smt version of the 2n2222a), and then the next two stages with 2n2222a's (in TO-18 form). No other changes to the radio.

It worked fine for a few days, though the 2n2222a's would get hot to the touch in digital mode transmit (which I think is to be expected). Today I started to experience 'bouncing' power readings during transmit (as shown in the meter on my tuner) before the radio simply stopped putting out much power at all. Nothing feels hot...and nothing looks burned or heat stressed to the naked eye.

So...before I start replacing things, I wanted to ask how to diagnose the problem. Is it most likely that I cooked some transistors, and how do I best till which ones?

73

Sean

Re: Highest quality uBitx Case ever!

jim
 


On Saturday, September 1, 2018, 6:41:27 PM PDT, Adam Goler <adamgoler@...> wrote:


when in doubt, make it out of cardboard. 

a




sometimes ya just gotta go with what works for you
Jim