Date   
Re: Cool cheap oscilloscope for troubleshooting

Paul KL7FLR
 

AS Jerry outlined, if you have nothing a DVM is high on the list of needed test equipment. I spotted this yesterday and if I had nothing this would be on my list to order. Not a high precision unit but gets you several things in one package.  My first (not cheap) DVM 40 years wasn’t to accurate but so I made an error correction chart from a lab precision 0-100 vdc/ac and it served me for many years. The Simpson 260 was my first meter in 1970 and still like it.

https://www.mpja.com/Digital-Multimeter-4-Digit-6000-count/productinfo/35525+TE/

Paul

Kl7FLR

Wasilla, AK

Re: Antuino as a Spectrum Analyzer: Lots of birdies?

Jerry Gaffke
 

In those cases where the birdies are a problem,
a handful of external bandpass filters would cure it.


On Thu, Aug 1, 2019 at 04:41 PM, Jerry Gaffke wrote:
As a general purpose spectrum analyzer looking at noisy wideband incoming RF,
I'd expect a lot of false signals due to images and local oscillator harmonics.
In the discussion from Dec 28 of 2018 included below, Farhan suggests
that images could be dealt with in software.

Antuino as a Spectrum Analyzer: Lots of birdies?

Jerry Gaffke
 

Looking at the latest schematic up on github:
    https://github.com/afarhan/antuino
it appears that Antuino does not have any filtering up front.

That would work fine as an antenna analyzer or scaler network analyzer
or to check a transmitter for harmonics and spurs.  In those cases the
incoming RF will be just a few signals, perhaps the main signal of interest
and a few harmonics.  The crystal filter will almost always knock out the false signals.

As a general purpose spectrum analyzer looking at noisy wideband incoming RF,
I'd expect a lot of false signals due to images and local oscillator harmonics.
In the discussion from Dec 28 of 2018 included below, Farhan suggests
that images could be dealt with in software.

Anybody have any comments on how well the Antuino works as a 
spectrum analyzer?

Jerry, KE7ER


On Fri, Dec 28, 2018 at 08:05 PM, Ashhar Farhan wrote:
the challenge would be to eliminate the if image. this could be done when you sweep to both sides and eliminate the image reading in software. here is an example :
 
1. lets imagine that there is a signal at 10 mhz. for this, we set the local oscillator at 35 mhz (as the IF is at 25 mhz). how can we be certain that the signal we are resolving is not at 60mhz (60mhz - 35 mhz = 25 mhz)?
2. we can take a second reading by setting the local oscillator at 85 mhz. in this csse, thr 60 mhz response (if any) should show up. else we can confirm that the signal we resolved in step 1 is indeed a 10 mhz signal.
 
one has to be aware that such a system will be slow. lets imagine that you have to sweep 30 mhz. the crystal filter is 10 khz wide. hence, we will need 30,000/5 = 6000 readings. if we can get, 100 readings a second, this will take a minute to complete the scan. an alternative would be to have two filters, a crystal filter and a 4 or even 5 section LC filter at around 12 mhz. we could switch to the lc filter for large sweeps. my specan circuit has a suitable design.
 
you are aking what happens if there was signal at 110 mhz in step two? aaaah, you tell me!
 
- f

Re: New uBitX - Start up Questions...

TACTICAL.RADIO.GEAR@...
 

Does anyone know the LO Drive level being used with the double balanced mixers off-hand? I suppose I could look it up on the data sheet for the synthesizer, but not in a place to do that at the moment.
Christopher

Re: New uBitX - Start up Questions...

Steven
 

Thank so much Doug and Dave.  Will let you know the results this weekend when I have time to mess with projects.

Steven-KM4WIP

Re: AMP FOR UBITX

Vince Vielhaber
 

If all else fails, this should work anywhere:

https://www.ebay.com/itm/113838277396

Vince.

On 08/01/2019 04:29 PM, bill steffey NY9H wrote:
RF POWER AMP QRP TO 50 WATTS BITX & TEN TEC 405 10 TO 80
METERS is the title...

Re: AMP FOR UBITX

bill steffey NY9H
 

RF POWER AMP QRP TO 50 WATTS    BITX  &  TEN TEC 405   10 TO 80 METERS          is the title...


VERY SRI FOR THE BANDWIDTH

On 8/1/2019 1:03 PM, Michael Wells via Groups.Io wrote:
Quote: "I cannot find it on ebay"
try https://www.ebay.com/itm/RF-POWER-AMP-QRP-TO-50-WATTS-BITX-TEN-TEC-405-10-TO-80-METERS/113838277396

Re: AMP FOR UBITX

bill steffey NY9H
 

  ten tec 405      should come up  ...   works here...



On 8/1/2019 9:55 AM, Ron Stauffer wrote:
I cannot find it on ebay


From: BITX20@groups.io <BITX20@groups.io> on behalf of bill steffey NY9H <Ny9h@...>
Sent: Thursday, August 1, 2019 8:39:10 AM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] AMP FOR UBITX
 
already got rid of one  k3 ./p3,,,,,,


bill




On 7/31/2019 11:09 PM, Skip Davis via Groups.Io wrote:
> So your thinning out the crowd of equipment you have? Are you making room for the K4? Nice to see you are active on the reflectors.
>
> Skip Davis, NC9O
>> On Jul 31, 2019, at 19:11, bill steffey NY9H <Ny9h@...> wrote:
>>
>> FINALLY GIVING UP MY TT 405 AMP ...  ON EBAY
>>
>>
>> WORKED GREAT WITH MY UBITX !!!
>>
>> BILL NY9H
>>
>>
>>
>
>
>
>



Re: AMP FOR UBITX

barry halterman
 

Been trying to sell my K3S, that is listed on QRZ, but no inquiring minds yet.

Re: Cool cheap oscilloscope for troubleshooting

Donald <donwestpwl@...>
 

Okay, ignore my previous post. I just looked at the Digilent Analog Discovery2 and it appears to be a pc-based scope and will not have knobs and controls like a self-contained scope. The manual is large because of all the things the device will do. My apologies.

Re: Cool cheap oscilloscope for troubleshooting

Darwin EI3IHB
 

It would be great if HF Signals will produce & sell  an oscilloscope kit that will match the UBitX ...

Re: Issues with ordering the BITX40

Mike Short
 

I have one I will sell

On Thu, Aug 1, 2019 at 12:04 <dk3ts@...> wrote:
Really want the BITX40 but as I have a band specific use for it. The link still appears broken for purchasing since it's still taking me to a generic PayPal page.

Re: Cool cheap oscilloscope for troubleshooting

Donald <donwestpwl@...>
 

David Wilcox,

I have seen several "how to use an oscilloscope" videos on youtube, while looking for various ham-related videos. I did not watch any, but just about any of them should show you what the controls do, and how to read the display scale. I would start with the shortest one, as that might show everything you need.--Donald, KB5PWL

P.S. If a scope has an AC-mains power supply, check to see if the probe shield (probe ground clip) is connected to earth ground in the scope. If so, we should be aware of this, every time we connect the probe to a circuit.

On 8/1/2019 4:39 AM, David Wilcox via Groups.Io wrote:
Has anyone information on how to use the Digilent analog scope?  The reference manual reads like a college text book on its features but using it for ham radio testing for a newbie I need a simple book  with lots of pictures..... ha!

David J. Wilcox K8WPE’s iPad

Re: New uBitX - Start up Questions...

Doug Hall
 

Hi Steven,

Congrats on the upgrade to Extra Class. 

It sounds like you didn't wire the switch contacts in series with your +12V power, but instead you have the +12V power and ground going directly to P1 on the board. If you want the on/off switch to turn the radio on and off then you'll need to run the +12V leads from the rear panel power jack to one side of the pot-mounted switch and then another wire back from the other side of the switch to the +12V connections on P1. The connection diagram shows a switch in series with the power lead - that switch is the one that is part of the volume control.

As far as not being able to tune when the mic is plugged in, it definitely sounds like the radio is going into transmit mode when you plug in the mic. You can't change frequency while the rig is in TX mode. Remove the mic and check between the ground of the mic plug and the ring connector. I'm betting your ohmmeter will show a short there.

As far as initial setup - I had to do the BFO frequency adjustment on my radio when I built it. This involves putting the radio into setup mode and then selecting BFO adjustment from the menu. Then you turn the VFO knob until the audio passband is in the right place - basically until a sideband signal "sounds" right. If it's too far in one direction the audio will sound very tinny with no low frequency response. If it's too far in the other direction it'll sound muffled. When you're happy with the setting you press the PTT button once to save it. So you're gonna have to fix that mic short before you do this part since you need a working PTT button.

Good luck,
Doug K4DSP

Re: ubitx with Icom SM-6 desk mic

John Scherer
 

Awesome, thanks Skip!
--
John - N0CTL - Fulltime RV in a 40' motorhome

Re: New uBitX - Start up Questions...

_Dave_ AD0B
 

Congrats on the upgrade.

Definitely odd behavior. Is the radio going into transmit when you plug in the mic/ptt? That is what it sounds like to me. Check the wiring make sure that the resistor is across to the ptt.

Re: Issues with ordering the BITX40

dk3ts@...
 

Really want the BITX40 but as I have a band specific use for it. The link still appears broken for purchasing since it's still taking me to a generic PayPal page.

Re: AMP FOR UBITX

Michael Wells
 

Re: AMP FOR UBITX

Skip Davis
 

That’s good soooo..... are you on the list for the K4? I’m thinking about it still, if it sounds as good as the KX3 I’m on board. I primarily use the KX3 and really haven’t used the K3 in months.

Skip Davis, NC9O
847-331-4147

On Aug 1, 2019, at 09:39, bill steffey NY9H <Ny9h@...> wrote:

already got rid of one k3 ./p3,,,,,,


bill




On 7/31/2019 11:09 PM, Skip Davis via Groups.Io wrote:
So your thinning out the crowd of equipment you have? Are you making room for the K4? Nice to see you are active on the reflectors.

Skip Davis, NC9O
On Jul 31, 2019, at 19:11, bill steffey NY9H <Ny9h@...> wrote:

FINALLY GIVING UP MY TT 405 AMP ... ON EBAY


WORKED GREAT WITH MY UBITX !!!

BILL NY9H




Re: AMP FOR UBITX

Ron Stauffer
 

I cannot find it on ebay


From: BITX20@groups.io <BITX20@groups.io> on behalf of bill steffey NY9H <Ny9h@...>
Sent: Thursday, August 1, 2019 8:39:10 AM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] AMP FOR UBITX
 
already got rid of one  k3 ./p3,,,,,,


bill




On 7/31/2019 11:09 PM, Skip Davis via Groups.Io wrote:
> So your thinning out the crowd of equipment you have? Are you making room for the K4? Nice to see you are active on the reflectors.
>
> Skip Davis, NC9O
>> On Jul 31, 2019, at 19:11, bill steffey NY9H <Ny9h@...> wrote:
>>
>> FINALLY GIVING UP MY TT 405 AMP ...  ON EBAY
>>
>>
>> WORKED GREAT WITH MY UBITX !!!
>>
>> BILL NY9H
>>
>>
>>
>
>
>
>