Date   
a simple spur fix

Ashhar Farhan
 

so, there is one spur fix that is now consistently working for me.
among rhe solutions, i was looking for one that would be easy to apply.
first, the distortion in the 45 mhz amp is creating harmonic distortion. so a 0.3uh in series with a 10 pf is used across TP13 (output of the 45 MHz IF amp going to the front end mixer). 8 turns on T30-6 gives you 300nh.
second, there is a cross talk inside the Si5351 where the 12 mhz from the bfo leaks into the local oscillator. A 5uh in series with a 47 pf across C202 of the LPF will suppress it. 35 turns on T30-6 gives you 5uh.
- f

Re: KD8CEC 1.095 vs 1.097 Features and S-Meter #smeter #ubitx #ubitx-help

Praba Karan
 

Yes...sorry for wrong spelling


On Fri, Nov 9, 2018, 7:03 PM Evan Hand <elhandjr@...> wrote:
I believe you meant hamskey web Ian Lee web site.

Re: KD8CEC 1.095 vs 1.097 Features and S-Meter #smeter #ubitx #ubitx-help

Evan Hand
 

I believe you meant hamskey web Ian Lee web site.

Re: KD8CEC 1.095 vs 1.097 Features and S-Meter #smeter #ubitx #ubitx-help

Praba Karan
 

S meter using lm358 as sensor is very simple. One more sensor version is using another Arduino. For more info refer hamsky web.


On Fri, Nov 9, 2018, 12:23 AM David Posthuma <davep@...> wrote:
I have been using KD8CEC's 1.095 version of the Firmware and have been very happy with it. I am using a 3.7-inch Nextion display. My question is two-fold:
1) What extra benefits would I get for upgrading to 1.097? 
2) I need to add an S-Meter, what sensor and setups are best for either version?

Re: Ubitx wiring harness pics

Prathap Naidu
 

Hi Doug

For illustartion pupose it was left  there

Yes I know it can be taken out by inserting a pin into the notch

73

Pop

VU2POP

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Doug W
Sent: Thursday, November 08, 2018 8:13 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Ubitx wiring harness pics

 

Those unused wires come out of the connectors very easily.  Just push down on the tab on the connector with a needle or jeweler's screwdriver and pull them out.  You can put them back in if you need them later.  Although it looks tidy, those coils look scary to me.
--
www.bitxmap.com

Re: CEC firmware installation using a MAC

Tom, wb6b
 

Here is a list of links for ch340 drivers for both the Mac and Windows.

https://groups.io/g/BITX20/message/51600

If you do decide you want to run the CEC uBITX Memory Manager on a Mac this link may help.

https://groups.io/g/BITX20/message/50329

Tom, wb6b

Re: Transmit Problem

Wayne Leake
 

 Regarding the shielded enclosures, yup, most good radios are enclosed in metal cases.
 Receiver only is far less fussy.
 I was looking at a number of possible cases for my BITX, and decided on a BUD enclosure, all aluminum
 It is big enough for the HF Signal BITX40, but turns out not for another BITX I am assembling.
 Boards too wide to fit both exciter and PA boards in it.
 I see all these great looking plastic cases, but figured that I do not want to go with no shielding.
 Hence the one that will go into a cassette  deck case will have shielding.
 The ferrite beads have their places, but don't take the place of good shielding, which may also help prevent images and harmonics , plus spurs, from escaping.
 YMMV
 Wayne WA2YNE

Re: uBITX AGC - Adafruit TPA2016, A Success! #ubitx

Curt
 

Joe

I am contemplating same thing. Note the  nd6t website shows 2 different agc designs, and note the link to adding an RF gain control. This is one candidate location for the mosfet attenuator,  even without installing an RF gain control that so far I don't need. I also thought about it at the front of the audio chain. I wonder if the agc bias could be injected into the existing TR mosfet, if not easy to add a second mosfet there. Worth some experiments to see what works well.

Curt

Re: Boy Scout activity event

Art Olson
 

Bruce

I would like the details also. 
I am on QRZ or
Olson339  at Comcast dot net

73
Art N2AJO 


On Nov 8, 2018, at 9:34 PM, Bruce MacKinnon KC1FSZ <bruce@...> wrote:

Hi Jack:

I'll send you the details directly since this thread is off-topic.  Anyone else who is interested feel free to drop me a line.

73s,
Bruce KC1FSZ

Re: Boy Scout activity event

Bruce MacKinnon KC1FSZ
 

Hi Jack:

I'll send you the details directly since this thread is off-topic.  Anyone else who is interested feel free to drop me a line.

73s,
Bruce KC1FSZ

Re: DIGITAL FREQUENCY READOUT

RCC WB5YYM
 

The crystal is not "bad" 
http://www.hamskey.com/2018/05/frequency-adjustment-of-ubitx-si5351.html

Re: Tool advice: contemporary oscilloscopes and Spectrum Analyzers

Ashhar Farhan
 

it may interest the group, last year wes and bob drove me through the erstwhile Tektronix campus in Portland. 
Wes told me how tek pushed the technology envelope. they invented many things from storage displays, colour tubes to tunnel diodes! without tek there wouls have been no silicon valley as we know it.
that apart, some of our legends worked there and often workee together. wes, roy, jeff are all alumni of tek.
- f

On Fri, 9 Nov 2018, 05:03 Jerry Gaffke via Groups.Io <jgaffke=yahoo.com@groups.io wrote:
I spent a decade sitting in front of a 2465.
A very nice scope, you did some good work!

Jerry, KE7ER



On Thu, Nov 8, 2018 at 02:38 PM, Benton Holzwarth wrote:
Hi, Benton here, speaking from a 35+ Tek career completed earlier this year...   I spent my entire time there writing SW for mid-range o'scopes, starting with the 2465 and ending with the '5 Series' MSOs.

Re: DIGITAL FREQUENCY READOUT

MONEYSMITH
 

i must have a bad 25 mhz crystal? i will try to get closer to 25 mhz and see if that does the trick.


On 11/8/2018 5:19 PM, RCC WB5YYM wrote:
Being 1khz off is not "normal". It needs master calibration adjusted,  NOT BFO CALIBRATION. Mine is hardly ever 10 cycles off. 

Virus-free. www.avg.com

Re: DIGITAL FREQUENCY READOUT

RCC WB5YYM
 

Being 1khz off is not "normal". It needs master calibration adjusted,  NOT BFO CALIBRATION. Mine is hardly ever 10 cycles off. 

Re: DIGITAL FREQUENCY READOUT

MONEYSMITH
 

THE BOX ABOVE THE uBITX IS MY HB DIGITAL WATT METER AND SWR BRIDGE. THANKS FOR THE REPLY.

W4NFR

On 11/8/2018 1:41 PM, Vince Vielhaber wrote:
Did you check the 25MHz calibration of the si5351?  If that's off, everything will be.

Also, what is the box above your uBitx (the one with the display that has PWR:0 SWR: 0.00 and RF: 0.0)?

Vince.


On 11/08/2018 11:22 AM, MONEYSMITH wrote:
THIS IS WHAT  I SEE WHEN LISTENING TO 7.128

WILLIAM W4NFR



-------- Forwarded Message --------
Subject:     Re: [BITX20] DIGITAL FREQUENCY READOUT
Date:     Thu, 8 Nov 2018 08:19:45 -0800
From:     MONEYSMITH <w4nfr@...>
To:     BITX20@groups.io



THANK YOU FOR THE COMMENTS. I HAVE LEARNED TO LIVE WITH IT. I HAVE TEST
THE OFFSET WITH KNOWN STATIONS

THAT ARE ON FREQUENCY AND MY DISPLAY IS ALWAYS 1 KHZ LOW FROM THE
ACTUAL.  I SUPPOSE THE 1 KHZ OFFSET WORKS

FOR CW AND SSB AND MAY BE THE REASON FOR THE STRANGE THING.


On 11/8/2018 6:46 AM, Mark Pilant wrote:
Hi William.

MAYBE I AM MISSING SOMETHING, BUT ARE ALL uBITX V4.3 RADIOS HAVE A
ONE
KHZ LOW READOUT. FOR EXAMPLE, IF I HAVE A STATION ON 7.150 SELECTED,
IT READS OUT 7.149 FOR CLEAR RECEPTION. IS THIS NORMAL?
The short answer, maybe.  (I apologize if you already know the following;
but for those who do not...)

Digital frequency readout is only as accurate as the calibration of
the sending
and receiving stations.  (I had a recent thread going about the Si5351
calibration.)  I'm assuming you have done the recommended calibration
of your
uBitx.

Even with a calibrated uBitx, there is likely to be some drift due to
thermal
heating from any number of sources: the components themselves, ambient air
temperature, etc.  This being said, it is probably unlikely you would see
a 1 KHz drift.

The other possibility is the sending station is "off", they may say
they are
transmitting on 7.150 MHz, but in reality they are on 7.149 MHz. Without
knowing the calibration of the sending station, it is really impossible to
know for certain.

In the "good ol' days" of analog dials, you simply tuned for the best
reception
and went with that.  (This is one of the reasons, back then, operating
near
the band edges was not recommended :-)  I do it all the time with my
Collins
rigs: get close with the dial and then interpolate the frequency.

My suggestion, if you are confident of your uBitx's calibration, is not to
worry about it and enjoy the contact :-)

73

- Mark  N1VQW




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Re: Harmonics and Relay Replacement

Kees T
 

Ben, NO5K, also ran some LPF Transmission Charts on a "pristine" V3.0 board followed by ONLY changing the the relays to AXICOM relays .....same fixture setup, same cables, same test gear. The plots show somewhat better harmonics reduction with the AXICOM relays but the rolloff (a filter characteristic) is basically the same between the two as you would expect them to be. 

As I mentioned earlier the AXICOM relays DO show improvement but it's not the whole story.

The attached charts are small, but can be expanded. The goal is to get the general idea.  

73 Kees K5BCQ


STANDARD uBITX RELAYS


AXICOM RELAYS

Re: Transmit Problem

Evan Hand
 

I am pretty sure the .1 is .1uf =100nf. I agree with the 100 volt

Re: Tool advice: contemporary oscilloscopes and Spectrum Analyzers

Jerry Gaffke
 

I spent a decade sitting in front of a 2465.
A very nice scope, you did some good work!

Jerry, KE7ER



On Thu, Nov 8, 2018 at 02:38 PM, Benton Holzwarth wrote:
Hi, Benton here, speaking from a 35+ Tek career completed earlier this year...   I spent my entire time there writing SW for mid-range o'scopes, starting with the 2465 and ending with the '5 Series' MSOs.

Re: Tool advice: contemporary oscilloscopes and Spectrum Analyzers

Benton Holzwarth
 

Hi, Benton here, speaking from a 35+ Tek career completed earlier this year...   I spent my entire time there writing SW for mid-range o'scopes, starting with the 2465 and ending with the '5 Series' MSOs.

> Siglent, Rigol, Hantek, are good places to start for low-cost new gear.
>But you don't necessarily want to buy from the lowest bidder,

There was a story, repeated by a couple folks in one of the other AR mail lists, that Tek OEM'd some of our low-end scopes from Rigol.  They were apparently told this by a rep at one of the trade shows.  (I don't know if it was a manufacturer's rep or one of the distributors.)  I thought this was untrue and confirmed it with one of our guys that would know for certain.  If anyone repeats this story to you, they've either bought in on the lie or are trying to deceive you.

> I'm not aware of any other scope for which a firmware upgrade removes a marketing gimmick like that,
some people seem to assume it's true of all the new DSO's.

This, on the other hand, is true -- many of Tek's mid-range o'scopes can increase BW at least through some steps via the application of a license key.  It might be either a fob or application of an encrypted string or signed file.  (Some models do require a board-swap to attain the top BW level.)

Back in the day, for one of our scope lines that did actually implement BW differences with HW changes (I think it was the 2220/2230 pair) the lower BW model was actually *more* expensive to build.  It included a couple extra caps on each channel to roll off the BW early.  8*)

Benton 8nov18
--
NX7O
benton@...

Re: DIGITAL FREQUENCY READOUT

N5KBP
 

You need to calibrate the VFO.

--
N5KBP