Date   
Re: TIA amps modification

George
 

I do my experiments over V4 board. About AGC - I think to use UA1FA schematic - very simple but good analog circuit: IF amp of the signal output filter 12 MHz - amplitud detector-DC amp. 2 transistors, 2 diods. V-control brings delay to detector and also manual control over RF gain. I do not know about MSA but if it works good that is the result you would like to get. As for me I like 2-Gate field- effect transistors - this is my practice, experience(old one) and no more. Thanks for the info. Bes regards!

Re: FS: ubitx20 plus Univ Gray Case

Bill Robbins
 

 It is sold. Thanks to all that inquired.

Merry Christmas


On Dec 23, 2019, at 8:38 PM, Bill Robbins <wa8cdu@...> wrote:



uBitx V4  from HFsigs.  Sorry

On 12/23/2019 8:06 PM, Jerry Gaffke via Groups.Io wrote:
No such thing as a "uBitx20".

Is it a uBitx, and if so, then what version?
Is it a Bitx40?
If it has a Raduino, then it is one of the above.

If it's not one of the above, then you will have to tell us in detail where in came from and when.
Could be a Bitx20, and if so it could have come from any number of sources.
Some of them quite different.

Jerry



On Mon, Dec 23, 2019 at 04:41 PM, Bill Robbins wrote:
I have started this and have lost interest.  No audio.  Powers up fine.  Universal Grey Case from  Amateurradiokits.com.  $65 shipped to lower 48.

Re: How to get rid of Local FM broadcast stations #ubitx

Jerry Gaffke
 

Jack,

So what BCI filter do you like best?
Can you show us a response curve that you know goes with that particular filter.
Are filters with the small axial leaded inductors suitable for in-line with the uBitx antenna,
or do you only use those for a receiver?
What kind of caps do you use (I'd think 100v NPO)?

Digging around through old posts, I found that you had recommended several different AM BCI filters:

In this one your post shows little axial leaded inductors, the article has some big toroids, no idea if it is the same filter design (in pf and uH):
   https://groups.io/g/BITX20/message/39613

This one looks like the same values as the above article, but the graph is totally different (and I have no idea what the Y axis is):
    https://groups.io/g/BITX20/message/72920

This one has the same graph as the above article, but has totally different values:
    https://groups.io/g/BITX20/message/67270

There may be others, that was just what I found in 3 or 4 minutes.

I had just recommended that last one to VU3ONX, in part because of the graph, 
and because using T50-6 toroids seemed like a good idea on a 10w uBitx.
On the other hand, those inductors should choke off most of the 3.5+MHz energy so perhaps
the smaller axial leaded guys are fine.

Jerry, KE7ER 



On Mon, Dec 23, 2019 at 01:57 PM, Jack, W8TEE wrote:
Thanks, Gwen. Also, the filter has a very low insertion loss and costs under a couple of dollars to build for a QRP rig.

Inline image

Re: FS: ubitx20 plus Univ Gray Case

Bill Robbins
 

uBitx V4  from HFsigs.  Sorry

On 12/23/2019 8:06 PM, Jerry Gaffke via Groups.Io wrote:
No such thing as a "uBitx20".

Is it a uBitx, and if so, then what version?
Is it a Bitx40?
If it has a Raduino, then it is one of the above.

If it's not one of the above, then you will have to tell us in detail where in came from and when.
Could be a Bitx20, and if so it could have come from any number of sources.
Some of them quite different.

Jerry



On Mon, Dec 23, 2019 at 04:41 PM, Bill Robbins wrote:
I have started this and have lost interest.  No audio.  Powers up fine.  Universal Grey Case from  Amateurradiokits.com.  $65 shipped to lower 48.

Re: FS: ubitx20 plus Univ Gray Case

Bill Robbins
 

Ok.  Sorry. I don’t have the packaging anymore so I’ll have to look on the board.


On Dec 23, 2019, at 8:07 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

No such thing as a "uBitx20".

Is it a uBitx, and if so, then what version?
Is it a Bitx40?
If it has a Raduino, then it is one of the above.

If it's not one of the above, then you will have to tell us in detail where in came from and when.
Could be a Bitx20, and if so it could have come from any number of sources.
Some of them quite different.

Jerry



On Mon, Dec 23, 2019 at 04:41 PM, Bill Robbins wrote:
I have started this and have lost interest.  No audio.  Powers up fine.  Universal Grey Case from  Amateurradiokits.com.  $65 shipped to lower 48.

Re: FS: ubitx20 plus Univ Gray Case

Jerry Gaffke
 

No such thing as a "uBitx20".

Is it a uBitx, and if so, then what version?
Is it a Bitx40?
If it has a Raduino, then it is one of the above.

If it's not one of the above, then you will have to tell us in detail where in came from and when.
Could be a Bitx20, and if so it could have come from any number of sources.
Some of them quite different.

Jerry



On Mon, Dec 23, 2019 at 04:41 PM, Bill Robbins wrote:
I have started this and have lost interest.  No audio.  Powers up fine.  Universal Grey Case from  Amateurradiokits.com.  $65 shipped to lower 48.

Re: V6 radino on V5 board?

mm0bef@...
 

I think the control cables are the same but the pin numbering for them have been reversed by mistake by Farhan in the v6 schematic. Ill figure this out when i get time to put screen in. Or ill check v5 and v6 code for the pin assignments that would tell if they are the same.
73
MM0BEF_____Brian

Re: How to get rid of Local FM broadcast stations #ubitx

Jerry Gaffke
 

I was wrong when I said this:
    "You need a low pass filter, not a high pass filter."
You are both sort of right.

The title of this thread is about FM broadcast, for which we should use a low pass
.
But VU3ONX is having trouble with an AM broadcast station.
Since the ubitx operates above the AM broadcast band, he wants a high pass filter.
And the two filters I pointed him to were both high pass.
I just got a couple words mixed up.

Hopefully, he doesn't also have a nearby FM broadcast station.

Jerry, KE7ER



On Mon, Dec 23, 2019 at 03:38 PM, Keven Pittsinger wrote:
The FM band is 88-108 MHz, IIRC.  The HF frequencies are 29.7 MHz on down for us.  You wanna stop the FM broadcast freqs, so you wanna use a low pass.
 
Hide quoted text

 


On Mon, Dec 23, 2019 at 4:01 PM Martin Potter <ve3oat@...> wrote:
Jerry wrote :
"You need a low pass filter, not a high pass filter."

No, high pass is correct.  Pass high frequencies, but block low frequencies.  Pass the HF stuff and block the lower frequency BC stuff.

The filters pointed to in the links are mis-labelled.  They are high-pass.  Capacitors across the top pass the high frequencies and block the lower frequencies.  Inductors going to ground drain off the low frequencies, letting the higher frequencies pass by.  High-pass, not low-pass.

If the interference is truly from the FM BC stations, and not their AM-band counterparts, then a low-pass filter would be appropriate.

73,
... Martin   VE3OAT



FS: ubitx20 plus Univ Gray Case

Bill Robbins
 

I have started this and have lost interest.  No audio.  Powers up fine.  Universal Grey Case from  Amateurradiokits.com.  $65 shipped to lower 48.

Bill

uBitx using 5 inch display

N7XG
 

Anyone out there in uBitx land that has used a 5 inch display with the uBitx?

Re: How to get rid of Local FM broadcast stations #ubitx

Keven Pittsinger
 

The FM band is 88-108 MHz, IIRC.  The HF frequencies are 29.7 MHz on down for us.  You wanna stop the FM broadcast freqs, so you wanna use a low pass.


On Mon, Dec 23, 2019 at 4:01 PM Martin Potter <ve3oat@...> wrote:
Jerry wrote :
"You need a low pass filter, not a high pass filter."

No, high pass is correct.  Pass high frequencies, but block low frequencies.  Pass the HF stuff and block the lower frequency BC stuff.

The filters pointed to in the links are mis-labelled.  They are high-pass.  Capacitors across the top pass the high frequencies and block the lower frequencies.  Inductors going to ground drain off the low frequencies, letting the higher frequencies pass by.  High-pass, not low-pass.

If the interference is truly from the FM BC stations, and not their AM-band counterparts, then a low-pass filter would be appropriate.

73,
... Martin   VE3OAT




Re: How to get rid of Local FM broadcast stations #ubitx

Martin Potter
 

Jerry wrote :
"You need a low pass filter, not a high pass filter."

No, high pass is correct. Pass high frequencies, but block low frequencies. Pass the HF stuff and block the lower frequency BC stuff.

The filters pointed to in the links are mis-labelled. They are high-pass. Capacitors across the top pass the high frequencies and block the lower frequencies. Inductors going to ground drain off the low frequencies, letting the higher frequencies pass by. High-pass, not low-pass.

If the interference is truly from the FM BC stations, and not their AM-band counterparts, then a low-pass filter would be appropriate.

73,
... Martin VE3OAT

Re: How to get rid of Local FM broadcast stations #ubitx

Jack, W8TEE
 

Thanks, Gwen. Also, the filter has a very low insertion loss and costs under a couple of dollars to build for a QRP rig.

Inline image


Jack, W8TEE

On Monday, December 23, 2019, 4:45:27 PM EST, Gwen Patton <ardrhi@...> wrote:


In Jack's filter, those are axial-lead inductors, not coils, but whatever. I built one of those for my Cricket 30 to cut down on BCI, and it works REALLY well. Tayda has those specific values in stock, too. That's where I bought mine.

73,
Gwen, NG3P

--
Jack, W8TEE

Re: How to get rid of Local FM broadcast stations #ubitx

Gwen Patton
 

In Jack's filter, those are axial-lead inductors, not coils, but whatever. I built one of those for my Cricket 30 to cut down on BCI, and it works REALLY well. Tayda has those specific values in stock, too. That's where I bought mine.

73,
Gwen, NG3P

Re: Audio Buzzing

N7XG
 

Anthony,

It is at 100%. When I lower it it gets real loud.

Re: Audio Buzzing

Anthony Gomes
 

N7XG,

If you have loaded the CEC Nextion display screen. It should be under "Home" -> "LCD Setting". Screen picture of your Nextion display will be helpful. As I have a 3.5' screen and the menu layout is bit different for 5' & 7' display.

Anthony
VU3JVX

Re: Audio Buzzing

N7XG
 

Can you give me some information how to adjust brightness?

Re: V6 mic connector - compatibility

Ashhar Farhan
 

It is wired with a 3.5 mm audio jack. The tip is mic, the ring is ptt and the sleeve is ground. It was kept this way so you can use regular audio cables to the computer.



On Mon 23 Dec, 2019, 10:49 PM Arv Evans, <arvid.evans@...> wrote:
Iz Oss

Properly wired it it is compatible with any rig that supports an electret type microphone. 
These have an internal FET that needs a small voltage and possibly a DC isolating
capacitor (capacitor need depends on circuit layout). 

If one wants to use a standard Icom, Yaseu, etc. microphone with a uBITX  then you
need to know the circuit layout of that unit and adapt your microphone to that layout. 

Dynamic or crystal microphones may not provide sufficient signal output to drive an
input that is designed for an electret microphone.  Dynamic microphones may also
require an isolating capacitor to block DC  from the microphone and a resistor to
adjust microphone DC bias to what it would be if an electret microphone were used. 


Arv  K7HKL
_._


On Mon, Dec 23, 2019 at 9:47 AM iz oos <and2oosiz2@...> wrote:

Hi all, I see the ubitx V6 comes with a stock mic. Is this compatible to any brand, Icom, Yaesu or Kenwood?

Re: V6

Bill Cromwell
 

Hi,

You can never have too many radios. But I don't a V6 and no plans for one right now. I am getting by just fine with my V3 :)

73,

Bill KU8H

On 12/23/19 11:44 AM, iz oos wrote:
Gosh, I'm the only only one not having a V6! Need one!!!!
Il 23/dic/2019 08:09, "Dave Dixon" <@DAVEDIXONG0AYD <mailto:@DAVEDIXONG0AYD>> ha scritto:
Hi,
       Just had confirmation my V6 is on its way seasons greetings
to all.Dave G0AYD
.
PS.I have a main board for a bitx 40 and am still looking for a
complete raduino for it..
--
bark less - wag more

Re: How to get rid of Local FM broadcast stations #ubitx

Jerry Gaffke
 

VU3ONX:

This thread is about interference from FM broadcast stations, which are up around 100 mhz.
Your post of   https://groups.io/g/BITX20/message/73876
indicates that you are having trouble with an AM broadcast station, way down around 1 mhz.
You need a low pass filter, not a high pass filter.

Here is one that W8TEE describes, looks like a good solution to me:
    https://groups.io/g/BITX20/message/67270
It consists of 4 caps and 3 coils,  it does not include the resistors.
It is symmetrical, so it doesn't matter which end is which.
The photo in that post shows it connected up to some other rig, not a uBitx.
But I believe Jack simply inserts that filter in line with his antenna, before it gets to his uBitx.
That seems like the easiest and lowest risk way to do it.
If building it for the uBitx, I would use the T50-6 toroids and 100 volt rated NPO capacitors.

These filters could be installed only in the receive path of the uBitx,
leaving the transmitted signal untouched. 
Here's a post where somebody does this mod to the uBitx:
    https://groups.io/g/BITX20/wiki/uBITX-AM-BCI-Filter
He has cut the trace between K3 pin 11 and K1 pin 12, the cut is not shown
because it is underneath the new filter board.
The red lines indicate wires from both ends of the cut trace into the new filter.
The blue lines indicate ground wires from the filter to the uBitx ground plane.
This method is guaranteed not to disturb your transmitted signal, as the cut
trace only carries the received signal.  However there is a slight chance that
since we are allowing your interfering signal into the box, it will somehow couple
into the receiver, going around the filter (I doubt this would be a problem).

Even though those two filters have completely different values for the coils and caps,
my guess is that either filter would work, using either method of installing it.

There have been other AM broadcast filters mentioned in the forum.
I have no idea what works best, as I live far from any AM broadcast station.
Perhaps others forum members could speak up.

Iz Ooz asked:
>  To have a better understanding of the problem, if you have an attenuator available, 10-20db, do you still hear the broadcast interference?

He is suggesting that you reduce the strength of all signals coming in from your antenna.
If a 10dB reduction in signal strength is sufficient for the uBitx receiver to not hear this AM station,
then we know that the filter need not be all that effective.
We would also want to know the frequency of the AM  broadcast station.

If you have such attenuators, go ahead and try this.
If not, I suggest you just build the filter that W8TEE described, put that in line with the antenna, see if it works.

If you want to experiment with building attenuators, look over this webpage:
    https://www.electronics-notes.com/articles/radio/rf-attenuators/pi-t-bridged-resistor-values-table-calculator.php%20%20%20%2096%2071,%20%20%2061%20248
Use the second schematic for a pi section attenuator.
For a 10dB attenuator, the table shows that the two R3 resistors should be around 96 ohms,
and the single R4 resistor should be 71 ohms.  Anything within 10% of those values would be fine.

Jerry, KE7ER


On Sun, Dec 22, 2019 at 09:26 PM, <vu3onx@...> wrote:
Hello Jerry Gaffke,
Thank you for your details troubleshooting tips.
Details of my uBitx is at https://groups.io/g/BITX20/message/73904

I dont have a battery. So I kept my PSU connected.

I use a metal box. Still I wrapped using kitchen aluminum foil.

Following your steps, I observed that the moment I connect my antenna cable, I start getting the local broadcast. 
So is it concluded that I need High pass filter?

Could you please suggest any DIY High pass Filter ?

73
vu3onx