Just now got my August 2018 copy of QST, a ham publication by the ARRL here in the states.
Has a very positive review of the Bitx40 starting on page 44, built with Sunil's enclosure.
Expect a wave of new forum members.
Jerry, KE7ER
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Re: Screen showing only blocks ?
Well, So I caught the culprit !!!? Red Handed or should i say RED FACED ...A classic nube move, yep the nincompoop plugged the screen on upside down, If i catch up with him you bet he will get a good tongue lashing.
oh i forgot my name.......
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Buying just the stock standard vanilla #Radiuno (no uBitx)
#radiuno
I previously purchased a Radiuno by itself for use in homebrew projects and would like another.? I don't want to take the time to source parts or build any of the expanded/extended/redesigned Radiunos at this time, exciting and good as they may be.
I cannot find the "Buy a Radiuno" button on hfsignals.? Have they been withdrawn from sale?
regards Paul VK3HN
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Re: RD16HHF1 power curve flattening...some
of course "snail mail shipping-- about 30 0r 40 days ti India but you might get faster? if in US.
On Thu, Jul 19, 2018 at 12:32 AM, Kevin Rea <reakevinscott@...> wrote: How long does it take you to receive things from polida2008 ? ? Kevin ? ? From: [email protected] <[email protected]> On Behalf Of Ashhar Farhan
Sent: Tuesday, July 17, 2018 10:44 PM
To: [email protected]
Subject: Re: [BITX20] RD16HHF1 power curve flattening...some ? Are you sure that the pins are not shorting?? ? I too suspect the devices? OP bought.? He could remove them and test with a DMM for the correctness of pinout. ?I am currently depending for my RD hhf and hvf devices, on an ebay seller " polida2008" after having suffered fake ones from another seller. ?This seller is now operating with another seller name "?5hk1584 " ?While i have no business deal with this seller(s), I do enjoy genuine devices for my hobby.? Hope it helps.
? On Wed, Jul 18, 2018 at 9:02 AM, Kevin Rea <reakevinscott@...> wrote: On Thu, Mar 8, 2018 at 05:14 PM, "John" <passionfruit88@...> wrote: Hi John,
did you mount the new pot in the front or? back or just leave it on the breadboard ?
kevin rea
lancaster, calif.
k6rea
?
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Re: RF power chain mods and improvements..
Glen, I understand that while mpsh10 might possibly be faked, the smd version mmbth10 is still genuine even with Chinese sellers.like ebay etc
sarma
vu3zmv
On Thu, Jul 19, 2018 at 5:32 AM, Glenn <glennp@...> wrote: That's interesting on the MPSH10's.?? They seemed to work well for me in my testing but I might add my MPSH10's were bought some 10 years ago.?? I wonder if they too, have succumbed to the Chinese(?) re-branding of some other inferior part?
glenn vk3pe
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Re: RF power chain mods and improvements..
On Wed, Jul 18, 2018 at 02:42 PM, Nick VK4PLN wrote:
Would you say the 2n2222A were better candidates than 2n5109? that is in regards to flatness of output across the bands?
Where in the world did you get that idea? Price and availability and poor reading.? The list was from common and easy that solves many? users needs (good at 80-17M) to exotic and better (for 20mhz and up) but maybe trickier due to higher FT.
A technical Question/ Learning session if you wouldnt mind Allison/ Others:
So to set the bias of these BJT we are changing a resistor to get a certain amperage.
Lets take the pre-driver #1, Q90, for instance: is the bias set by R81 and R82(voltage divider)? and if so, according to your earlier post we measure the voltage drop across the emitter resistor, and then calculate the mA. Now you state 20-30ma? where does that figure come from? is it different for each BJT we try?
Run Q90 at 30ma and watch it heat up.? Its a ridiculous current to run for a stage that may produce 10mW and a device that is not designed to run at that current level. (BFR106 datasheet).? I've suggested numbers for this as UNDER 20ma even with the 3904 (mine with the factory 3904 was running at 33ma!). To correct the bias, change the base to collector resistor R81.? The predrivers have to produce a bit more but they are in parallel so 20ma each is fine Also running more than that is just wasting current to produce heat, not RF.? ? The driver in mine (3904s) were idling at 39ma each and the IR temp meter was show them at 145F. Again its a impractically high current for most devices used in that spot.? ?Many of the devices have a sweet spot and its a balance of wasted power as heat and circuit requirements for impedance and? power out.? ?So it is both different for each device and also a consideration to keep from cooking it. However if you think you have a better number...? I'm waiting.? FYI if you read the whole chain I've repeated myself so many times, I give up. Allison
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Re: RF power chain mods and improvements..
There is worked and "worked".? I keep getting this.? If they solve your problem wonderful.
Others tried them and they didn't really help much compared to other devices.
In context they worked in that they were marginally better than the 2n3904s, but compared
to the 2n2222A or 2n2219 they were not very good.? ?Compared to 2n3866 they were poor.
I went and bought some to test and they came from a reliable source (I don't use Ebay or aibaba)
and they were genuine Fairchild branded parts.? All showed good beta/HFE but they didn't achieve
generally better power over bandwidth.? They looked good on the curve tracer too.? ?I used a few
for another project at lower power and they performed well there at 29mhz but I was only asking
them to deliver 50mW.? ?The uBitx driver has to supply much more.
If you put them in, the radio will still work, but you will not get much improvement.?
Allison
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Jack
Been holding off on building the board I bought until you have reached a final one. Assume the board I have isn¡¯t compatible with your modified changes
toggle quoted message
Show quoted text
On Jul 18, 2018, at 7:51 PM, Jack Purdum via Groups.Io < jjpurdum@...> wrote:
We changed the board again (now on V4) because we were not happy with the noise level. Al has that figured out and we hope to order new Beta boards in the next couple of days.?
Jack, W8TEE
On Wednesday, July 18, 2018, 5:38:59 PM EDT, Tim - M0THM < tim@...> wrote:
Hi Jack,
Just wondering how things are coming along.
Cheers
Tim
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Re: Screen showing only blocks ?
This really ought to be prominent on the website and included with kit: "On power-up, screen may be either blank or showing blocks. Adjust Raduino's contrast pot for clarity of text".
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Re: RF power chain mods and improvements..
That's interesting on the MPSH10's.?? They seemed to work well for me in my testing but I might add my MPSH10's were bought some 10 years ago.?? I wonder if they too, have succumbed to the Chinese(?) re-branding of some other inferior part?
glenn vk3pe
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Re: K5BCQ click fix 2nd generation installed
#ubitx
Looks like I spoke too soon. When I re-assembled and plugged back in, I had no audio.
It does go into TX when I key the mic. I'm not sure if its getting out though.
So bummed, but this was my first time soldering surface mount components and I figured it wouldn't be perfect on the first attempt.
More to come...?
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We changed the board again (now on V4) because we were not happy with the noise level. Al has that figured out and we hope to order new Beta boards in the next couple of days.?
Jack, W8TEE
On Wednesday, July 18, 2018, 5:38:59 PM EDT, Tim - M0THM <tim@...> wrote:
Hi Jack,
Just wondering how things are coming along.
Cheers
Tim
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Re: Screen showing only blocks ?
Well, the only pot I saw was on the board that the screen was actually plugged into. Tried end to end, no effect at any point. Hope i didn't mess things up worse.. Sill could here digital noise in ear phones as i tuned so maybe not all lost. I planed and have 3.5 screen on way, but would like to get this thing up and running before trying to install new soft/hardware. One other observation is that the row of blocks or on the bottom row of screen only, also the 5 volt regulator got to hot to hold finger on in less that a minute or two,,, something amiss here me thanks.... what say you - someone - anybody - any ????? :)
chuck
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Re: Screen showing only blocks ?
Was wondering what that did, will try it next power up. Thanks much for the info!
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Re: RF power chain mods and improvements..
Hi Allison.
Would you say the 2n2222A were better candidates than 2n5109? that is in regards to flatness of output across the bands?
A technical Question/ Learning session if you wouldnt mind Allison/ Others:
So to set the bias of these BJT we are changing a resistor to get a certain amperage.
Lets take the pre-driver #1, Q90, for instance: is the bias set by R81 and R82(voltage divider)? and if so, according to your earlier post we measure the voltage drop across the emitter resistor, and then calculate the mA. Now you state 20-30ma? where does that figure come from? is it different for each BJT we try?
Thank you for taking the time to edumacate us.
73 Nick VK4PLN
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#ubitx Power output improvement mods - my results :(
#ubitx
Liking to tinker, I installed very cheap tiny socket PINS (cheap sockets were hard to find) in place for the 6 3904s near the final.
I stumbled upon some 2N2369A transistors on the web. Here my results? (don't get excited)
Ver 4 ubitx
Band? Power output
80 14 watts
40? ?8
20? 13
15? 7
10? 2? ??
The results with the 2369As WAS IDENTICAL!!!
The 3904 has a TYPICAL Ft of 300Mhz? ? and hfe 100-400? power dissipation of 625mW or 1.5W (both figures on datasheet)
The 2369 has a MINIMUM Ft of 500Mhz???and hfe 40-120???power dissipation of 360mW
NOW,? I realize I did not think this out fully.
I had memories of the 3904 as audio frequency devices and the 2369 was advertised as high frequency
I saw the higher Ft and nice metal enclosure (=better heat dissipation)? and fell for them.
A cheap way to learn a bit,
Off to Google and comments in our forums for some ideas.
Why is the power output bump on 2o meters?? One would expect a diminishing value as frequency goes up.
I'll be happy with a nice stable 10 watts across the bands.?
Aren't these little ubitx's more fun than Heathkits from days of old?
73, Bo W4GHv since '54? ? ?(I put that because I enjoy thinking BACK and am HOPING to make it to the next sunspot peak!)
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Hi Jack,
Just wondering how things are coming along.
Cheers
Tim
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Re: Screen showing only blocks ?
Did you try to adjust the pot on the back of the display board ? It only effects the screen and if too high you get blocks? and if too low nothing.
On Wed, Jul 18, 2018 at 4:30 PM, <chuckr@...> wrote: Just finished my first ubitx v4 build and things are not working as expected...Thanks first of all for any and all help. My main symptom is that on power up the display is showing a string of blocks on the bottom row.. Somewhere about two thirds to the right is one blocking dimly blinking. A quick disconnect before something went poof and subsequently with longer power on no change was had. I then plugged some ear buds into and could here some birdies and other odd sounds etc. as? I turned the tuning control. Have any of you all had or know of what this problem is or points too. I know this isn't much info to go on but all support/help/advice is appreciated.
73
chuck
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Re: Getting ready to build my first Ubitx ver 4
There's a how to build stock for the V3:? /g/BITX20/wiki/uBITX-Assembly If feel up to it, making a v4 version of that wiki page would be a great help to others. Patrick | W7PEA
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VK3HN
Lee
Nick VK4PP