Date   
Using MPSA18 darlington in the driver? #parts #ubitx

Ghericoan
 

I have a roughly ten of these MPSA18 darlingtons coming in the mail to play with and was wondering if they would increase the drive level in the ubitx?

I mean, I can always just solder them in and see what may happen, but I was curious if anyone else had rebuilt the driver stage and played around with it?
--
----------
N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist

SolderSmoke #204 is available -- uBITX Mania!

Bill Meara
 

Re: boosting the power on 28 MHz #ubitx

Skip Davis
 

I should have sometime this afternoon to try them out I’ll let you know my results. Also I have documented before and after mod readings at various test points in the TX driver stages so I can forward that to you too. 

Skip Davis, NC9O

On May 5, 2018, at 10:12, Ashhar Farhan <farhanbox@...> wrote:

I am keen to know how this works as it is an easy upgrade to give to the production guys
- f

On Sat, 5 May 2018, 19:14 Skip Davis via Groups.Io, <skipnc9o=yahoo.com@groups.io> wrote:
Thanks Farhan, this is a great design and has been a easy platform to modify both hardware and firmware. 
I might try part of your mod to see what results I get too. 

Skip Davis, NC9O

On May 5, 2018, at 09:35, Ashhar Farhan <farhanbox@...> wrote:

4 watts, similar power as his mod.
- f

On Sat, 5 May 2018, 19:04 Skip Davis via Groups.Io, <skipnc9o=yahoo.com@groups.io> wrote:
Farhan what power out are you seeing with this modification at 28 MHz? 
I have installed Howard’s mods to the driver and in seeing 4 watts with RV1 at 2/3 ccw. 

Skip Davis, NC9O

On May 5, 2018, at 08:13, Ashhar Farhan <farhanbox@...> wrote:

peeps,

28 Mhz is unusually open for the last one week. I realized that our ubitx output is woefully low. Here is a fix that I made today, if some of you can try it out, let me know if it works as well.

Step #1 Increase the predriver gain towards the higher frequencies
The predriver Q90 has a emitter degeneration capacitor C81 (0.1uf) and and R83 (10 ohms). I replaced the C81 with a 470 pf and the R83 with 5 ohms. With this, the emitter reactance decreases with increasing frequency, yielding higher gain beyond 14 MHz.

Step #2 Take off the feedback from the IRF510s. 
Just remove the R261, R262 (both are 220 ohms) to open up the gain.

Let me know if this mod is replicable?

- f

Re: FT8 on uBITX experiences

Vince Loschiavo
 

Hi all

i wanted to comment about FT8 using the uBitx. 
I got hooked on the Bitx 40 and followed Jacks and Allards mods, and decided to switch I’ve t to the uBitx. And of course deciding which thread to follow for mods, hit on KD8CEC approach early on. 

It it was a bit tough to follow his website, as I’m not a software guy, but with a few questions and missteps I have the rig modified to the latest. 
Very difficult keeping up with Dr. Ian he the. Jumps to interfacing with a raspberry Pi. So I figured what the hell I’ll try that. Uggg, but again with a little help I now have a Pi3 running WSJTX and plugged into the uBitx with CAT control and for the last month strictly using it on multiple bands on FT8. Is it possible yes does it work?  Yes if you are looking for a challenge try it. If you do t take some risks you never advance. 
My 2 cents and Props to Dr Ian Lee for his interest and support to the group. 
Next is to get the Pocket WSJTX working.  

N2AIE
Vince

Re: boosting the power on 28 MHz #ubitx

Ashhar Farhan
 

I am keen to know how this works as it is an easy upgrade to give to the production guys
- f

On Sat, 5 May 2018, 19:14 Skip Davis via Groups.Io, <skipnc9o=yahoo.com@groups.io> wrote:
Thanks Farhan, this is a great design and has been a easy platform to modify both hardware and firmware. 
I might try part of your mod to see what results I get too. 

Skip Davis, NC9O

On May 5, 2018, at 09:35, Ashhar Farhan <farhanbox@...> wrote:

4 watts, similar power as his mod.
- f

On Sat, 5 May 2018, 19:04 Skip Davis via Groups.Io, <skipnc9o=yahoo.com@groups.io> wrote:
Farhan what power out are you seeing with this modification at 28 MHz? 
I have installed Howard’s mods to the driver and in seeing 4 watts with RV1 at 2/3 ccw. 

Skip Davis, NC9O

On May 5, 2018, at 08:13, Ashhar Farhan <farhanbox@...> wrote:

peeps,

28 Mhz is unusually open for the last one week. I realized that our ubitx output is woefully low. Here is a fix that I made today, if some of you can try it out, let me know if it works as well.

Step #1 Increase the predriver gain towards the higher frequencies
The predriver Q90 has a emitter degeneration capacitor C81 (0.1uf) and and R83 (10 ohms). I replaced the C81 with a 470 pf and the R83 with 5 ohms. With this, the emitter reactance decreases with increasing frequency, yielding higher gain beyond 14 MHz.

Step #2 Take off the feedback from the IRF510s. 
Just remove the R261, R262 (both are 220 ohms) to open up the gain.

Let me know if this mod is replicable?

- f

Re: boosting the power on 28 MHz #ubitx

Skip Davis
 

Thanks Farhan, this is a great design and has been a easy platform to modify both hardware and firmware. 
I might try part of your mod to see what results I get too. 

Skip Davis, NC9O

On May 5, 2018, at 09:35, Ashhar Farhan <farhanbox@...> wrote:

4 watts, similar power as his mod.
- f

On Sat, 5 May 2018, 19:04 Skip Davis via Groups.Io, <skipnc9o=yahoo.com@groups.io> wrote:
Farhan what power out are you seeing with this modification at 28 MHz? 
I have installed Howard’s mods to the driver and in seeing 4 watts with RV1 at 2/3 ccw. 

Skip Davis, NC9O

On May 5, 2018, at 08:13, Ashhar Farhan <farhanbox@...> wrote:

peeps,

28 Mhz is unusually open for the last one week. I realized that our ubitx output is woefully low. Here is a fix that I made today, if some of you can try it out, let me know if it works as well.

Step #1 Increase the predriver gain towards the higher frequencies
The predriver Q90 has a emitter degeneration capacitor C81 (0.1uf) and and R83 (10 ohms). I replaced the C81 with a 470 pf and the R83 with 5 ohms. With this, the emitter reactance decreases with increasing frequency, yielding higher gain beyond 14 MHz.

Step #2 Take off the feedback from the IRF510s. 
Just remove the R261, R262 (both are 220 ohms) to open up the gain.

Let me know if this mod is replicable?

- f

Re: For those keeping track of uBITX shipping times #ubitx

Gerry Hull
 

Ordered April 15, notice last Tuesday and deliver3d via DHL yesterday to New Hampshire.

73, Gerry W1VE

Re: For those keeping track of uBITX shipping times #ubitx

Tom Christian
 

I ordered my 2nd ubitx kit last Sunday on 29 April. DHL picked up the package from Hyderabad yesterday on Friday 4 May. The package is due to arrive this Tuesday 8 May. So the total time now is 9 days from order to arrive.  This is so much faster than the 2 months for the first ubitx!  Great job HF Signals!!
Tom
AB7WT

Re: boosting the power on 28 MHz #ubitx

Ashhar Farhan
 

4 watts, similar power as his mod.
- f

On Sat, 5 May 2018, 19:04 Skip Davis via Groups.Io, <skipnc9o=yahoo.com@groups.io> wrote:
Farhan what power out are you seeing with this modification at 28 MHz? 
I have installed Howard’s mods to the driver and in seeing 4 watts with RV1 at 2/3 ccw. 

Skip Davis, NC9O

On May 5, 2018, at 08:13, Ashhar Farhan <farhanbox@...> wrote:

peeps,

28 Mhz is unusually open for the last one week. I realized that our ubitx output is woefully low. Here is a fix that I made today, if some of you can try it out, let me know if it works as well.

Step #1 Increase the predriver gain towards the higher frequencies
The predriver Q90 has a emitter degeneration capacitor C81 (0.1uf) and and R83 (10 ohms). I replaced the C81 with a 470 pf and the R83 with 5 ohms. With this, the emitter reactance decreases with increasing frequency, yielding higher gain beyond 14 MHz.

Step #2 Take off the feedback from the IRF510s. 
Just remove the R261, R262 (both are 220 ohms) to open up the gain.

Let me know if this mod is replicable?

- f

Re: boosting the power on 28 MHz #ubitx

Skip Davis
 

Farhan what power out are you seeing with this modification at 28 MHz? 
I have installed Howard’s mods to the driver and in seeing 4 watts with RV1 at 2/3 ccw. 

Skip Davis, NC9O

On May 5, 2018, at 08:13, Ashhar Farhan <farhanbox@...> wrote:

peeps,

28 Mhz is unusually open for the last one week. I realized that our ubitx output is woefully low. Here is a fix that I made today, if some of you can try it out, let me know if it works as well.

Step #1 Increase the predriver gain towards the higher frequencies
The predriver Q90 has a emitter degeneration capacitor C81 (0.1uf) and and R83 (10 ohms). I replaced the C81 with a 470 pf and the R83 with 5 ohms. With this, the emitter reactance decreases with increasing frequency, yielding higher gain beyond 14 MHz.

Step #2 Take off the feedback from the IRF510s. 
Just remove the R261, R262 (both are 220 ohms) to open up the gain.

Let me know if this mod is replicable?

- f

Re: boosting the power on 28 MHz #ubitx

Ashhar Farhan
 

The power will level off around 13 watts.
- f

On Sat, 5 May 2018, 18:44 , <docame12@...> wrote:
How will this affect the lower freqs?

Re: ND6T AGC implementation for uBIT-X

Bill Carpenter
 

I asked Kees and he is going to produce SMT kits only, no through hole.

73, Bill NZ0T

Re: boosting the power on 28 MHz #ubitx

docame12@...
 

How will this affect the lower freqs?

boosting the power on 28 MHz #ubitx

Ashhar Farhan
 

peeps,

28 Mhz is unusually open for the last one week. I realized that our ubitx output is woefully low. Here is a fix that I made today, if some of you can try it out, let me know if it works as well.

Step #1 Increase the predriver gain towards the higher frequencies
The predriver Q90 has a emitter degeneration capacitor C81 (0.1uf) and and R83 (10 ohms). I replaced the C81 with a 470 pf and the R83 with 5 ohms. With this, the emitter reactance decreases with increasing frequency, yielding higher gain beyond 14 MHz.

Step #2 Take off the feedback from the IRF510s. 
Just remove the R261, R262 (both are 220 ohms) to open up the gain.

Let me know if this mod is replicable?

- f

Re: ND6T AGC implementation for uBIT-X

lance.kemp@...
 

Hope I’m not too late to jump on the bandwagon. I would like to put myself down for two of each kit please. First time post for me and loving the information and help nature of everyone. Especially helpful for an electronics noob like me. 

Cheers
Lance  VK6LMK 
Bickley, Western Australia 

Re: schematic vs motherboard

Skip Davis
 

Yes Tom same on my board, it appears that this was changed when the board layout was done because the silkscreen and parts placement match.

Skip Davis, NC9O

On May 4, 2018, at 18:08, Tim Gorman <tgorman2@...> wrote:

All,

While troubleshooting my ubitx problem it looks to me like C32 and R37
are swapped on the motherboard from what the schematic shows.

It shouldn't make any difference in the circuit operation since they
are in series anyway.

But it would be nice to know if anyone else has seen this.

tim ab0wr


Re: Small 3-5A brick power supply recommendation?

Howard Fidel
 

A will either use a regional A priority mail box, or send it USPS retail ground depending on where you live in the continental US. The price is $20 paid by  Pay Pal or personal check.

Howard

On 5/4/2018 9:57 PM, alans77 via Groups.Io wrote:
Howard: I think USPS priority mail is the way to go also.

Alan


Re: Small 3-5A brick power supply recommendation?

alans77@...
 

Howard: I think USPS priority mail is the way to go also.

Alan

Works good!

Frank King
 

I checked into the Oregon Emergency net at 0100Z tonight. It looks like I am putting out about 8 watts on my meter. Net control was Larry in Hood River, about 140 miles east. I heard stations from all over the NW. Happy camper!
Frank
AA7XA

Re: Nano Capability with 2.8" TFT Displays

K9HZ <bill@...>
 

I think this was directed at me…  Yes what I meant by “glitch” was that the resources of the Nano are really stretched when you throw in a touch screen. My experimentation with the larger format TFT and touch screen resulted in having to touch the screen multiple times in order to get the “touch” to register as an action.  The Nano was not recognizing the touch consistently with the existing library.. so that’s what I meant by “glitch”.

 

 

Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

 

Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

 

Owner – Operator

Villa Grand Piton – J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com

Like us on Facebook! facebook icon

 

Moderator – North American QRO Group at Groups.IO.

 

email:  bill@...

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Kees T
Sent: Friday, May 4, 2018 11:57 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Nano Capability with 2.8" TFT Displays

 

Bill,

Are you saying it was glitchy with the 5", 7", or 2.8" displays and what does "glitchy" mean ?

I would be interested in CW capability too like some of the K3NG code. He even has a "code reader" and lots of message memories good for contesting. Nothing better than a uBITX for CW, DSP just has too much signal latency.

73 Kees K5BCQ


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