Date   
Re: Went Dead

Bill Watkins
 

Wondering about complimentary/equivalence???

image1.png


On Jun 15, 2018, at 14:24, Bill Watkins <kf7yxs@...> wrote:

Thanks,

So, one mosfet is shorted.  I'm no electronics wiz so I have to ask basic questions.  It's an irf510, right?  Fry's electronics shows no item of that name.  Is there another company that makes something generically the same, or is there a similar item available at Fry's that I can replace it with?

Is that the real issue?  With the zero ohms from source to drain on one transistor and with the unit powering up when brown wire disconnected is shorted mosfet the answer to this problem (at least short-term, anyway)?

Bill
K0WHW

Re: SI5351 quadrature VFO

Hans Summers
 

Hi Farhan

> My question wasn't clear enough. I was asking if 
> the library worked to 290 MHz. 

Ah I see... have no idea about the library... my various firmware implementations do all work up to 290MHz. The integer /4 limitation anyway results naturally out of my code since I'm using even integer MultiSynth anyway (except for the one exception where I need three independent general purpose outputs).

73 Hans G0UPL 

Re: Went Dead

Bill Cromwell <wrcromwell@...>
 

Hi Bill,

Mouser has them under a dollar. Buy a couple of spares and ask them ship them via usps (lower cost first class postage). So far I haven't fried mine :)

73,

Bill KU8H

On 06/15/2018 03:24 PM, Bill Watkins wrote:
Thanks,

So, one mosfet is shorted. I'm no electronics wiz so I have to ask
basic questions. It's an irf510, right? Fry's electronics shows no
item of that name. Is there another company that makes something
generically the same, or is there a similar item available at Fry's that
I can replace it with?

Is that the real issue? With the zero ohms from source to drain on one
transistor and with the unit powering up when brown wire disconnected is
shorted mosfet the answer to this problem (at least short-term, anyway)?

Bill
K0WHW
--
bark less - wag more

Re: SI5351 quadrature VFO

Ashhar Farhan
 

Which library do you recommend with the synth kit?

- f

On Sat, Jun 16, 2018 at 1:04 AM, Hans Summers <hans.summers@...> wrote:
Hi Farhan

> My question wasn't clear enough. I was asking if 
> the library worked to 290 MHz. 

Ah I see... have no idea about the library... my various firmware implementations do all work up to 290MHz. The integer /4 limitation anyway results naturally out of my code since I'm using even integer MultiSynth anyway (except for the one exception where I need three independent general purpose outputs).

73 Hans G0UPL 


Re: SI5351 quadrature VFO

Jerry Gaffke
 

Jerry's code "overflows" at anything above 875/8 = 109 mhz because no attempt was made
to support integer mode output msynth values, that should be clear enough from the comments.
Actually what it does is shut down that output clock to make it clear that you have screwed up. 

Any output msynth of less than 8.0 must be an integer of either 6 or 4.
Greater than 8.0, the output msynth can take on fractional values.
So with the vco at the max of 900 mhz (I was using 875mhz), the absolute max output 
frequency for fractional output msynths within the datasheet spec is 900/8 = 112.5mhz.
Not 150 mhz.

The 150 mhz limitation of many si5351 libraries comes from the fact that 6*150=900 mhz,
so that's the limit of an output msynth integer divide of 6.
An output msynth divide of 4 requires some special case code, though it is fairly trivial.

To add support to the si5351bx routines for integer output msynth values and fractional vco msynth values
is easy enough, but doubles the amount of flash required.  Also complicates the user interface.
No point in doing any of that when targeting the uBitx.

Phase noise from the vco will be proportional to the output frequency. 
At some point I'd expect trouble there, especially if tripling the si5351 output. 

At what frequencies do you see these sidebands?
Is this with the si5351bx routines?
Or with integer output msynth values using some other library to generate 112.5mhz and greater clocks?

At some point, I think this is best moved to an si5338.
Or an si549 if you really want to get crazy.  1500mhz max.

Jerry, KE7ER



On Fri, Jun 15, 2018 at 11:58 am, Ashhar Farhan wrote:

Hans,
My question wasn't clear enough. I was asking if the library worked to 290 MHz. Above 150 Mhz, integeral divider is needed. There was some overflow with jerry's code. 
That apart, i see some sidebands about -40dbc on both sides of the signal, a few hundred kilohertz on either sides. They appear only on specific frequencies. 
I am really interested in using the Si5351 on 435 MHz. I pushed a 150 Mhz signal out of the Si5351 into a 450 Mhz band pass filter (doubly tuned, promixally coupled). It gave about -4dbm out of the band pass filter, A MMIC raises it to the obligatory +7dbm. 
 
- f

Re: TX Debug Steps?

Ralph Mowery
 

It is tough to do much with some test equipment.  Everyone should have some kind of way to check the SWR at a minimum and that can be used as a rough guess as to the output.  Been in that shape many years ago.

To see if you have any output you can use the time honored way of a light bulb. 

For the ubitx you can use the small bulbs such as the tail light of a car.  I tried it just to see if it would work.  Depending on how much output you have it will light up the bulb somewhat, usually much less than the nominal 12 volt of a car.  Do not do this test very long, just a few seconds to see if the bulb will light.

The ubitx will probably blow the older # 47 and 2 D cell flashlight bulbs  
I am not sure if it would light one of the 5 to 10 watt 120 volt bulbs or not.

Just make sure it is a filament bulb and not one of the newer LED types.




On Fri, Jun 15, 2018 at 2:54 PM, W8SWG <ebay@...> wrote:
I have been running my uBitX very successfully using WSJT-X for about a week and now all of a sudden I cannot make any contacts at all.  I am still receiving perfectly I do not seem to be getting out even with close contacts.  The indicator says that it is transmitting and the heat sinks warm up but still no contact.

I am a noob and have almost nothing in test equipment except for a VOM.  Anyone have any suggestions?
_._,_._,_


Re: Went Dead

Gwen Patton
 

I bought some spares from Mouser very easily.

https://www.mouser.com/ProductDetail/Vishay-Siliconix/IRF510PBF?qs=sGAEpiMZZMshyDBzk1%2fWi1F3z9PgzPBnjAas2zQPJco%3d

Re: Went Dead

Clark Martin
 

With the symptoms described there is a microscopic chance it’s something other than a shorted MOSFET. You might want to consider replacing both final transistors. Whatever killed the one that is shorted may have damaged the other. Make sure to buy several spares, this may not be the first time you need to replace them.

I’d strongly suggest putting a fuse inline, this may protect the final transistors from future damage and also protect your power source from overload if it does happen again.

Make sure you replace the thermal grease between the transistors and heatsink. Don’t forget to set the bias adjustment for the new transistor (you should probably verify the bias adjustment for the other.

Below are some reputable sources for replacement IRF510s:

https://www.mouser.com/ProductDetail/Vishay-Siliconix/IRF510PBF?qs=sGAEpiMZZMshyDBzk1%2fWi1F3z9PgzPBnjAas2zQPJco%3d


https://www.jameco.com/z/IRF510-Major-Brands-Transistor-IRF510-MOSFET-N-Channel-100-Volt_209234.html?CID=GOOG&gclid=EAIaIQobChMI7cCJuLTW2wIVEsNkCh3wXQNhEAkYASABEgLGAfD_BwE

https://www.arrow.com/en/products/irf510pbf/vishay?utm_source=google&utm_campaign=g-shp-us-fet_transistors&utm_medium=cpc&utm_term=PRODUCT+GROUP&gclid=EAIaIQobChMItr2Vt7TW2wIVQ41-Ch1L7gdWEAkYASABEgLXDfD_BwE&gclsrc=aw.ds&dclid=CIaN0ti01tsCFUzLZAodA5cAUg

https://www.alliedelec.com/vishay-pcs-irf510pbf/70078850/?mkwid=s6sX9YbUa&pcrid=30980760979&gclid=EAIaIQobChMItr2Vt7TW2wIVQ41-Ch1L7gdWEAkYBCABEgKC6PD_BwE

http://www.newark.com/vishay/irf510pbf/n-channel-mosfet-100v-5-6a-to/dp/63J7301?mckv=sNl2veeHe_dc%7Cpcrid%7C81515566701%7Cplid%7C%7Ckword%7C%7Cmatch%7C%7Cslid%7C%7Cproduct%7C63J7301%7C&gross_price=true&CATCI=pla-148794670821&CAAGID=20376568701&CMP=KNC-GUSA-GEN-SHOPPING-63J7301&CAGPSPN=pla&gclid=EAIaIQobChMItr2Vt7TW2wIVQ41-Ch1L7gdWEAkYBiABEgK82_D_BwE&CAWELAID=120185550001121418

Clark Martin
KK6ISP

On Jun 15, 2018, at 12:24 PM, Bill Watkins <kf7yxs@...> wrote:

Thanks,

So, one mosfet is shorted. I'm no electronics wiz so I have to ask basic questions. It's an irf510, right? Fry's electronics shows no item of that name. Is there another company that makes something generically the same, or is there a similar item available at Fry's that I can replace it with?

Is that the real issue? With the zero ohms from source to drain on one transistor and with the unit powering up when brown wire disconnected is shorted mosfet the answer to this problem (at least short-term, anyway)?

Re: uBitx has a bit too crispy / semi-distorted audio even on low signal levels #ubitx #ubitx-help

Mike
 

Hi!

There is also overload on weak signals
Tried Q70 mod: that didnt help, still distortion
Tryed several speakers and several headphones: the same
Tried two different ubitx units: no change, same distortion
I received the units around 15june2018. They were sent in June 2018. Could this be a bad batch?
Anyone else have experienced this? Any more hints?

Re: Transmitter Mods

Dave de WS1ETI <docame12@...>
 

Howard, I asked before and could not find my answer as it probably got lost somewhere in the myriad pages of this forum. WHere can I find your address? Maybe you could send me an email at docame12@...?  I really appreciate it.

Thanks!
Dave, WS1ETI

Re: VOM Advice? Simpson 260

Ralph Mowery
 

They go back before that.  I have 2.  One bought new around 1990 and one that I got when my  dad died.  Not sure how old that one is but I know he had it in the 1950's.

Both seem to be with in spec as verified by my digital Fluke.  

Now even the 'Free " harbor freight meters seem very good for general testing.  I have verified 4 of them and they are all close enough for hobby testing. Usually the last digit would only be one to three numbers off   As they were 'free' I have them laying around several places in the basement just so I do not have to walk across the room.  One in my truck.  

With many of the digital meters going for less than $ 20, probably any of them would be fine now.  If they do 'blow up', not too much lost.
I just would not want to use them on anything with over 120 volts that could put out over an amp of current.  After seeing some safety films put out by Fluke one gets skiddish when working on some 480 volt 3 phase equipment that can put out over 500 amps like I worked on  with the inexpensive meters.  

On Fri, Jun 15, 2018 at 3:22 PM, <tituskz1g@...> wrote:
You can't go wrong with a Simpson Model 260 VOM.  Yes, it dates to the 1960' or '70's, but it's a well-built meter that will serve you nicely for years.  It uses batteries for ohms measurements, so you'll need to replace them about every 18 months.  You can find Simpson 260 meters on Ebay for $US 50 or less.  No semiconductors inside, just resistors.  I've had mine since 1970 and couldn't do basic V, O, or M measurements without it.  Buy a set of good test leads and you're all set forever.
--
Jon Titus, KZ1G
Herriman, UT USA

Re: Went Dead

Arv Evans
 

Just replacing the IRF-510 devices may not be enough.  Something caused the failure.  Was it
an intermittent antenna connection that drove SWR too high?  Or was it a power spike that
punched through the MOSFET structure?
Finding and fixing the cause might be the first order of business, before replacing the damaged
components.

Arv  K7HKL
_._


On Fri, Jun 15, 2018 at 1:43 PM Clark Martin <kk6isp@...> wrote:
With the symptoms described there is a microscopic chance it’s something other than a shorted MOSFET.  You might want to consider replacing both final transistors.  Whatever killed the one that is shorted may have damaged the other.  Make sure to buy several spares, this may not be the first time you need to replace them.

I’d strongly suggest putting a fuse inline, this may protect the final transistors from future damage and also protect your power source from overload if it does happen again.

Make sure you replace the thermal grease between the transistors and heatsink.  Don’t forget to set the bias adjustment for the new transistor (you should probably verify the bias adjustment for the other.

Below are some reputable sources for replacement IRF510s:

https://www.mouser.com/ProductDetail/Vishay-Siliconix/IRF510PBF?qs=sGAEpiMZZMshyDBzk1%2fWi1F3z9PgzPBnjAas2zQPJco%3d


https://www.jameco.com/z/IRF510-Major-Brands-Transistor-IRF510-MOSFET-N-Channel-100-Volt_209234.html?CID=GOOG&gclid=EAIaIQobChMI7cCJuLTW2wIVEsNkCh3wXQNhEAkYASABEgLGAfD_BwE

https://www.arrow.com/en/products/irf510pbf/vishay?utm_source=google&utm_campaign=g-shp-us-fet_transistors&utm_medium=cpc&utm_term=PRODUCT+GROUP&gclid=EAIaIQobChMItr2Vt7TW2wIVQ41-Ch1L7gdWEAkYASABEgLXDfD_BwE&gclsrc=aw.ds&dclid=CIaN0ti01tsCFUzLZAodA5cAUg

https://www.alliedelec.com/vishay-pcs-irf510pbf/70078850/?mkwid=s6sX9YbUa&pcrid=30980760979&gclid=EAIaIQobChMItr2Vt7TW2wIVQ41-Ch1L7gdWEAkYBCABEgKC6PD_BwE

http://www.newark.com/vishay/irf510pbf/n-channel-mosfet-100v-5-6a-to/dp/63J7301?mckv=sNl2veeHe_dc%7Cpcrid%7C81515566701%7Cplid%7C%7Ckword%7C%7Cmatch%7C%7Cslid%7C%7Cproduct%7C63J7301%7C&gross_price=true&CATCI=pla-148794670821&CAAGID=20376568701&CMP=KNC-GUSA-GEN-SHOPPING-63J7301&CAGPSPN=pla&gclid=EAIaIQobChMItr2Vt7TW2wIVQ41-Ch1L7gdWEAkYBiABEgK82_D_BwE&CAWELAID=120185550001121418

Clark Martin
KK6ISP

> On Jun 15, 2018, at 12:24 PM, Bill Watkins <kf7yxs@...> wrote:
>
> Thanks,
>
> So, one mosfet is shorted.  I'm no electronics wiz so I have to ask basic questions.  It's an irf510, right?  Fry's electronics shows no item of that name.  Is there another company that makes something generically the same, or is there a similar item available at Fry's that I can replace it with?
>
> Is that the real issue?  With the zero ohms from source to drain on one transistor and with the unit powering up when brown wire disconnected is shorted mosfet the answer to this problem (at least short-term, anyway)?




Re: TX Debug Steps?

Jerry Gaffke
 

I used to use a 40 watt incandescent bulb with my old novice 6146 crystal oscillator, that can work.
Though be aware of this statement  "Tungsten-filament incandescent lamps exhibit a very-high positive
temperature coefficient of resistance with the cold filament resistance being approximately 10% of the hot filament resistance." 

from:  http://www.allegromicro.com/~/media/Files/Technical-Documents/an295012-A-Primer-On-Driving-Incandescent-Lamps.ashx

So the load that the lamp presents will vary drastically with power, you can't just measure the filament with an ohmmeter.

I think you are better off  spending $0.10 each on some Xicon 3W 200 ohm resistors, item 283-200-RC from Mouser,
four of those in parallel give you a 50 ohm load that can dissipate 12 Watts.
Then inspect the RF voltage across that load using a diode RF probe and your Harbor Freight DVM.

Jerry, KE7ER
 


On Fri, Jun 15, 2018 at 12:40 pm, Ralph Mowery wrote:
It is tough to do much with some test equipment.  Everyone should have some kind of way to check the SWR at a minimum and that can be used as a rough guess as to the output.  Been in that shape many years ago.
 
To see if you have any output you can use the time honored way of a light bulb. 
 
For the ubitx you can use the small bulbs such as the tail light of a car.  I tried it just to see if it would work.  Depending on how much output you have it will light up the bulb somewhat, usually much less than the nominal 12 volt of a car.  Do not do this test very long, just a few seconds to see if the bulb will light.
 
The ubitx will probably blow the older # 47 and 2 D cell flashlight bulbs  
I am not sure if it would light one of the 5 to 10 watt 120 volt bulbs or not.
 
Just make sure it is a filament bulb and not one of the newer LED types.
 
 
 
 

Re: Went Dead

Bill Watkins
 

I was in middle of a wspr transmission. Had done several within the hour. Possibly didn’t wait long enough for pa to cool. I don’t know. 

Had contact on 20 with good signal report earlier.  Radio was working. 

Re: TX Debug Steps?

Doug W
 

All good advise but something else to think about...  The WS in WSJT is weak signal.  K1JT has brewed up such strong magic that people have reported decoding signals without any antenna attached at all.  Are you sure you still have a reasonably resonant antenna connected?  Depending on your location you could touch a coat hanger to your rig and probably receive a decent amount of traffic,  What is your antenna set up?
--
www.bitxmap.com

Re: TX Debug Steps?

Doug W
 

A second even easier idea, are you positive you are still getting audio from your computer (or whatever) into the radio?  Connect the audio line going into your radio to a speaker and make sure you are hearing something.
--
www.bitxmap.com

Size of uBITX Surface Mount Resistors/Capacitors ? #ubitx

 

Does anyone know off-hand what size the surface mount caps and resistors are that are on the uBITX board ? 
Are they 1206 ? 

Michael VE3WMB 

Re: Nextion Displays >> warning

Joe
 

I have ordered mine from www.Robotshop.com
 two 3.2 inch Enhanced version and one 7 inch basic - all good.

Joe
VE1BWV

On Fri, Jun 15, 2018 at 4:37 AM Glenn <glennp@...> wrote:
I purchased what appeared to be a Nextion display according to the description, off ebay recently. Cost was $12.  It arrived ok but does not work. The Nextion editor warns that displays with the prefix "TJC" are not compatible. On ebay they are being sold as Nextion displays but appear to be some sort of copy. (Hardly unusual) ( Genuine Nextion displays start at more like $18-20.)

The Nextion editor does not allow them to be uploaded with files.  Apparently there was supposed to be a way, with some previous versions of the Nextion Editor which I found and also tried, but to no avail.

So a warning about using 'Nextion" displays, but actually shown as TJC types, they should not be purchased.  Unfortunately ebay (as usual) sellers do not tell us this. Some don't even show the part number on the back in a picture.

glenn

Re: Size of uBITX Surface Mount Resistors/Capacitors ? #ubitx

G8HAV
 

Hi, They are 0805 SMD.


Peter Paul Fox G8HAV
Mid-Cheshire Amateur Radio Society
5 Llandovery Close
Winsford
Cheshire CW7 1NA 

Group Controller
Dane Valley RAYNET 
Tel: 01606553401 (H)
Tel: 07919315547 (M)


From: BITX20@groups.io <BITX20@groups.io> on behalf of Michael Babineau <mbabineau.ve3wmb@...>
Sent: 15 June 2018 21:18:32
To: BITX20@groups.io
Subject: [BITX20] Size of uBITX Surface Mount Resistors/Capacitors ? #ubitx
 
Does anyone know off-hand what size the surface mount caps and resistors are that are on the uBITX board ? 
Are they 1206 ? 

Michael VE3WMB 

Re: Went Dead

ajparent1/KB1GMX
 

Bill,

The list is not a direct replacement list each has differences.

If you replace the failed device replace both with the same vendors IRF510.
(BUY TWO).  IF they charge more than 1.50$ each its robbery.

When you replace them you must reset Bias.  NExt time whats the temperatures.

Allison