Date   
New siglent on the way

Gordon Gibby <ggibby@...>
 

Notified last night that it may arrive next Wednesday. I never had a spectrum analyzer in my life until the little $110 unit from China and now this.....

Took a course a week or two back from the county and they had a $30,000 service monitor with built-in Spectrum analyzer.

Retiring from the practice of medicine January 10, 2020. Will have a lot more time!!

Tons to do!

Gordon

Re: Poor mans spurs and harmonics check with uBitx and commercial radio

Bill Lamm
 

So you have me curious?!  ate you using the touchstone free app or the paid app? I have an RTL-SDR and a uBITX on order

Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio #ubitx-help #ubitx

_Dave_ AD0B
 

The transmit is sticking on. Maybe the left most relay is stuck.

Re: Microphone choices

_Dave_ AD0B
 

The obvious choice is the stock electret button mic. I usually get subjective comments of being great sounding.Have a desk mic made from a weighted desk lamp and some flex tubing. Used the stock switch opening to put momentary contact switch. For a portable hand mic I used an old cb mic and took out the stock element after finding it too weak and replaced the element with another electret button glued into the space. The mic lost a lot of weight.

If you are going to travel with the radio consider make sure the raduino board is securely bolted in and not just hung on the connector. I make a 3d printed plate that does that.

Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio #ubitx-help #ubitx

Don Klier
 

Well I have  5  board  never  had  any of  the  problems  as  everyone  has...But  I still cannot get  my blue  screen  to work..  radio  works  fine   Don  W0DJK

Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio #ubitx-help #ubitx

ronmhauser@...
 

From a troubleshooting perspective, I would disconnect the power to the PA, un-solder the brown wire on the power connector, then you should be able to power up the radio and check receive.

73
--Ron
K0EIA

Re: Microphone choices

David Wilcox <Djwilcox01@...>
 

Let’s not forget Goodwill and Salvation Army thrift stores.  Was in one yesterday and mics, etc., were just sitting there collecting dust.  Super cheap too.  Lots of parts sitting there if one need unsoldering practice, and speakers up the Wazoo...... if you visited weekly you could build a ham station and a junque box full of parts in a month or so.  Who said ham radio was expensive?

Dave K8WPE since 1960.

David J. Wilcox K8WPE’s iPad

On Apr 10, 2019, at 9:32 AM, N8DAH <Dherron@...> wrote:

I bought one for my bitx40 they work out very nice. I take the element out and put it in a mini mic.

http://www.jlielectronics.com/microphones/com-mic-jli-52b/
--
David

 N8DAH
Kit-Projects.com

Shop is open!

Re: Maximum and minimum voltages for uBitX V5?

Dan Pflugrath
 

I have a uBITX version 3 and now a version 5.  On both I use a 4 cell LiPO battery to power the radios that when fully charged is 16.8 volts.  I run the LiPo through the main power switch and fuse to a LM317 voltage regulator for 12 volts (170 - 200 mA) to the main board and the full LiPo battery voltage to the PA .   I monitor the voltage on the LiPo battery to not go below 13.75 volts before recharging.

Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio #ubitx-help #ubitx

Clark Martin
 

If the output MOSFETs are heating up on power up with out being in transmit, they are toast.

Clark Martin
KK6ISP

On Apr 10, 2019, at 8:52 PM, Jens Kaemmerer <jens@...> wrote:

Since the IRF510 heatsinks are getting very hot very quickly right after turning on 
the radio - I am afraid to keep the radio on and potentially cause more damage. 

I am currently thinking of replacing the IRF510s first, hoping that this will fix the 
'overheating' issue. Will try the proposed measurements when the replacement 
IRF510s arrive.

Prior to this issue, I was able to receive all types of signals (SSB, CW, FT8, ...).

Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio #ubitx-help #ubitx

Jens Kaemmerer
 

Since the IRF510 heatsinks are getting very hot very quickly right after turning on
the radio - I am afraid to keep the radio on and potentially cause more damage.

I am currently thinking of replacing the IRF510s first, hoping that this will fix the
'overheating' issue. Will try the proposed measurements when the replacement
IRF510s arrive.

Prior to this issue, I was able to receive all types of signals (SSB, CW, FT8, ...).

-jens (KM6ZJV)

Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio #ubitx-help #ubitx

Ashhar Farhan
 

if the signals have fallen from the waterfall, that means you are unable to receive. IRF510s may not be involved. Are you able to receive SSB/CW signals? You should check your audio cable.

- f

On Thu, Apr 11, 2019 at 7:18 AM Clark Martin <kk6isp@...> wrote:
Check the supply current to the PA with a meter.  If it’s significantly higher than the idle current, say 250-300 mA it’s probably damaged.  To be sure, turn the bias pots to the full clockwise position and check the PA current again.  It should very low, less than 50mA.  If the FETs are damaged they’ll probably be drawing as much as before you dialed down the bias pots.

I would strongly suggest a fan and/or bigger heatsinks.

Clark Martin
KK6ISP

> On Apr 10, 2019, at 6:42 PM, Jens Kaemmerer <jens@...> wrote:
>
> I might have broken the IRF510 MOSFETs with FT8.
>
> This problem started during a longer sequence of FT8
> transmissions - abruptly all signals disappeared from
> the waterfall.
>
> The heatsinks used to get warm/hot only after a longer
> sequence of FT8 TX cycles. Now the heatsinks gets hot
> almost immediately after powering up the radio.
>
> Could this be an indication that the IRF510 MOSFETs
> have been damaged?
>
> How can I diagnose what is still working and what is not?
>
> Has anybody else experienced this problem? If yes,
> how can it be fixed?
>
> Thank you,
>
> -jens (KM6ZJV)
>
> PS: I was using the original heatsinks, radio has been working
> fine for 4 weeks.
>




Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio #ubitx-help #ubitx

Clark Martin
 

Check the supply current to the PA with a meter. If it’s significantly higher than the idle current, say 250-300 mA it’s probably damaged. To be sure, turn the bias pots to the full clockwise position and check the PA current again. It should very low, less than 50mA. If the FETs are damaged they’ll probably be drawing as much as before you dialed down the bias pots.

I would strongly suggest a fan and/or bigger heatsinks.

Clark Martin
KK6ISP

On Apr 10, 2019, at 6:42 PM, Jens Kaemmerer <jens@...> wrote:

I might have broken the IRF510 MOSFETs with FT8.

This problem started during a longer sequence of FT8
transmissions - abruptly all signals disappeared from
the waterfall.

The heatsinks used to get warm/hot only after a longer
sequence of FT8 TX cycles. Now the heatsinks gets hot
almost immediately after powering up the radio.

Could this be an indication that the IRF510 MOSFETs
have been damaged?

How can I diagnose what is still working and what is not?

Has anybody else experienced this problem? If yes,
how can it be fixed?

Thank you,

-jens (KM6ZJV)

PS: I was using the original heatsinks, radio has been working
fine for 4 weeks.

ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio #ubitx-help #ubitx

Jens Kaemmerer
 

I might have broken the IRF510 MOSFETs with FT8.

This problem started during a longer sequence of FT8
transmissions - abruptly all signals disappeared from
the waterfall.

The heatsinks used to get warm/hot only after a longer
sequence of FT8 TX cycles. Now the heatsinks gets hot
almost immediately after powering up the radio.

Could this be an indication that the IRF510 MOSFETs
have been damaged?

How can I diagnose what is still working and what is not?

Has anybody else experienced this problem? If yes,
how can it be fixed?

Thank you,

-jens (KM6ZJV)

PS: I was using the original heatsinks, radio has been working
fine for 4 weeks.





Re: CW key sticking with Nextion LCD

Joe Puma
 

At first I wrapped a barrel chock on the wires of Nextion. It helped a little. The I put a .01uf on the blue wire of Nextion and ground and that stopped the key from sticking.

Joe

On Apr 10, 2019, at 12:46 PM, d balfour <davesters@...> wrote:

I didn't follow the link but You might try a torrid on the orange line and/or between the raduino and nextion.


Re: v5 12m/10m Spectrums

ronmhauser@...
 

Hi Curt.  I had to prove it to myself using a spreadsheet when I started reading these, dBm or dBV doesn't matter when comparing peaks within one spectrogram.  Here's my math proof using the peaks from the file 24895_30mWpp_3W.jpg.  All the peaks in the spectrogram are relative to one volt.  The instrument doesn't know the input impedance of the system so it can't do the calculation to change them to dBm.  But all the peaks are using the same input impedance, whatever it is, so it doesn't matter.  The difference between peaks in dB is what we care about, looking for -43dB down from the fundamental.  Right?  For the record the transmitter is terminated in a 50 ohm dummy load and the cable to the instrument is also terminated in 50 ohms ... but mathematically it doesn't matter it's the same impedance at for both peaks in the calculation.




73
--Ron
K0EIA

Re: CW key sticking with Nextion LCD

_Dave_ AD0B
 

I didn't follow the link but You might try a torrid on the orange line and/or between the raduino and nextion.

Re: v5 12m/10m Spectrums

Curt
 

My concern is whether we are measuring a power ratio or a voltage ratio - I am suspicious we could be measuring the latter -- see

https://en.wikipedia.org/wiki/Decibel#Voltage

I am thinking that if the ubitx is loaded at 50 ohms that the instrument may be taking valid data.  But perhaps a conversion to power ratio is necessary.  40 dB in voltage corresponds to an amplitude ratio of 100, while in power it is 10000.  yes note this can be the difference between having spurs at - 43 dB or - 23 dB when the unit is power! 

See if you instrument offers a tutorial on this.  I am thinking that even though voltage is being sensed, possibly the instrument knows how to do the conversion to power (??). 

As I possess a ubitx (v4) with spurious around -33 to - 35 dBc in the upper bands on SSB - I was hoping your v5 to be much better, but I don't want us to jump to that conclusion without careful evaluation.  [The greater news - my box is compliant on SSB up to 17m, and now good on CW - 'just' with a relay transplant to add a second set of relays on a daughter board]. 

Curt

Re: v5 12m/10m Spectrums

ronmhauser@...
 

Well, the AD2 is really a (software defined digital) scope with FFT ... so the front end is a scope front end, the probes are high impedance voltage input.  Therefore the display is relative to voltage, not power.  I can't choose dBm ... BUT ... the measurement between the fundamental and the harmonics and spurs are relative, they are dB down from fundamental.  Changing the reference changes the scale on the left, but not the difference between the peaks.  (Unless I am doing the decibel math wrong, which is possible).

On mine -- on 12m -- with mike gain and RV1 turned down -- I'm calling it FCC compliant with all peaks 43dB down from the fundamental on 12m, either SSB or CW. 

73
--Ron
K0EIA

Re: CW key sticking with Nextion LCD

Joe Puma
 

Thanks Sam!

 

Sent from Mail for Windows 10

 


From: BITX20@groups.io <BITX20@groups.io> on behalf of Sam Tedesco <stedesco619@...>
Sent: Wednesday, April 10, 2019 9:25:17 AM
To: BITX20@groups.io
Subject: Re: [BITX20] CW key sticking with Nextion LCD
 

Re: Microphone choices

 

I bought one for my bitx40 they work out very nice. I take the element out and put it in a mini mic.

http://www.jlielectronics.com/microphones/com-mic-jli-52b/
--
David

 N8DAH
Kit-Projects.com

Shop is open!