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uBitX v.6 schematic / driver and finals transistor symbols / #v6 #ubitxv6


Todd Carney
 

Folks,

On Farhan's schematic for v.6, the pre-drivers, drivers, and finals transistors are drawn in a way I've never seen before. There's solid lines from the base of one transistor through the circle body of the transistor to the base of the next transistor. Examples include Q911 & Q912, Q92 & Q93, etc.


Is this a shorthand way of drawing parallel transistors (i.e., the bases are connected together)?

Thanks! Todd K7TFC


IW4AJR Loris <lorisbollina@...>
 

Hey Todd !!!
 
making the shoes to the flea on the schemes does not seem to me a constructive way to experiment !!!
 
I think the fantasy is dead !!! ... I have read many posts in this forum and I have come to the conclusion that humanity is shrinking more and more to simple and robotic stacks ... if something is not standardized it is out of the understanding of the robotic minds of the new computer humanity! !! !
 
Use a little imagination, if something is not "strictly" codified, USE IMAGINATION !!!! fly over the nonsense and get to the point !!!! you may discover the immense pleasure of using the brain !!!!
 
wishes of "beep .. beep" !!! 73 de IW4AJR Loris


Todd Carney
 

Loris--I guess something was lost in the translation from English to Italian and back to English, but I take it you can't answer my question. My non-robotic 'imagination' already suggested the shorthand idea, and now I'm looking for confirmation. Ciao!


Mick
 

Questa risposta non ha senso
--
 

73
Mick VA3EPM 


Gordon Gibby
 

Yes, they are in parallel. I was confused the first time I saw that with an earlier schematic years ago and checked it out.  (look at the actual board)’




On Nov 21, 2020, at 20:21, Mick <Mgsebele@...> wrote:

Questa risposta non ha senso
--
 

73
Mick VA3EPM 


Bob Lunsford
 

I've seen that on other schematics. Where there are more than one with the same arrangement of accompanying resisters, etc., the line is dashed and the notation "Q1, ... Qn" is written above the line to designate the transistors in the string.. It's done to conserve space on the paper and to avoid unnecessary confusion.

Want to talk about confusion with schematics? I worked for a machine tool company in New York for a year and one engineer owned his own machine tool company in the Philippines previously and he designed an automatic system for cutting rods into threaded shafts with all kinds of beveled areas, reliefs and retaining slots. The drawing for the machine was 40-ft long... The machine cut a shaft automatically in less than half an hour that took four times that when done by a human and with much more precision. Such machines are fascinating to watch, much like the first time you see a plotter drawing up a written document with fancy fonts, etc.

I know a draftsman/designer (WB4RVN) who can draw script that looks like it was done by a machine. I'm sure there are others equally talented. These people are artists in their own right. Calligraphy is indeed an art.

Bob — KK5R


On Saturday, November 21, 2020, 9:31:00 PM EST, Gordon Gibby <docvacuumtubes@...> wrote:


Yes, they are in parallel. I was confused the first time I saw that with an earlier schematic years ago and checked it out.  (look at the actual board)’




On Nov 21, 2020, at 20:21, Mick <Mgsebele@...> wrote:

Questa risposta non ha senso
--
 

73
Mick VA3EPM 


Todd Carney
 

Thanks, Gordon. I'm building from scratch so I didn't have a board to look at, and I wasn't smart enough to look at a picture or the layout file.

73, 
Todd K7TFC

On Sat, Nov 21, 2020, 6:30 PM Gordon Gibby <docvacuumtubes@...> wrote:
Yes, they are in parallel. I was confused the first time I saw that with an earlier schematic years ago and checked it out.  (look at the actual board)’




On Nov 21, 2020, at 20:21, Mick <Mgsebele@...> wrote:

Questa risposta non ha senso
--
 

73
Mick VA3EPM 


IW4AJR Loris <lorisbollina@...>
 

Hello Todd

It is extremely difficult to translate Italian into English ...
Italian is a complex and unique language in concepts and definitions, English is too simplistic a language to express certain concepts ... 
Do you want an example: 

tu sei -> you are 
voi siete -> you are 
tu hai -> you have 
voi avete -> you have 

it is enough for you ? .... Loris


IW4AJR Loris <lorisbollina@...>
 

Hey Todd .... HAHAHA I'm sorry ... Please "too simplistic a language" read "too simplistic language" ... HAHAHA ... BYE ... Loris


Gerard
 

hello,
I had already asked the question, but I did not get an answer
on the schematic  of ubitx 6, there are like 2 transistors mounted in parrallele on the final stage
We see an IRF510 and a RD15HV in //.
Maybe it’s a choice of transistor? You put one or the other?
I don’t quite understand the diagram

for traduction fron Italien, try reverso
Avevo già posto la domanda, ma non ho avuto risposta
sul piano dell'ubitx 6, ci sono come 2 transistor montati in parrallele sul piano finale
Vediamo un IRF510 e un RD15HV in parallelo.
Potrebbe essere una scelta di transistor? Si mette uno o l'altro?
Non capisco lo schema

Loris, se capisci questo, è che Reverso non funziona troppo male

cdt


 

Yes, you can use one or the other but not both. The pinout is different so Farhan has provided for both
solder pads.

Raj

At 22/11/2020, you wrote:
hello,
I had already asked the question, but I did not get an answer
on the schematic of ubitx 6, there are like 2 transistors mounted in parrallele on the final stage
We see an IRF510 and a RD15HV in //.
Maybe its a choice of transistor? You put one or the other?
I dont quite understand the diagram


SIMON ROSS <simonr5@...>
 

That confused me too. Mine won’t transmit so been faulty finding. This diagram doesn’t help much 😂


Bob Lunsford
 

It is common for a draftsman to use the double-slash ("//") tp denote a line that continues. Some use the double-tilde ("~~") instead. It is done to denote a "broken line" where it only means that a much too long line lengthens over a section of the drawing. I is an 'unspecified length' ... nothing more. I can, however, see it as an indication that one's particular radio may be opened and one or the other transistor may be found installed as the final transistor since the two may be electrically identical but made by different manufacturing firms and the particular firm's identification marking may be found on that transistor. It could be that the manufacturer of the transistors is the same, the marking only is printed on the transistor as bought/contracted by the buyer.

At one time there were over 250 brands of tires offered in America and only 17 manufacturers. When I worked many years ago in a radio-TV shop, there was a l17-inch BW TV that when opened was found to be identical but sold under four different brands; even the diagrams used the part numbers of the different brands but the schematic was identical. Japan at one time had a catalog of cassette tape drives which were offered to different sellers so they could be put in their cases and sold as THEIR cassette players, many buyers not suspecting that the cassette they purchased was identical to the one sold for XX dollars less/more but they chose the machine they bought because the box it was in appealed more to their likes and taste.

We live in a sometimes confused world.

Bob — KK5R

On Sunday, November 22, 2020, 6:07:19 AM EST, Gerard <kabupos@...> wrote:


hello,
I had already asked the question, but I did not get an answer
on the schematic  of ubitx 6, there are like 2 transistors mounted in parrallele on the final stage
We see an IRF510 and a RD15HV in //.
Maybe it’s a choice of transistor? You put one or the other?
I don’t quite understand the diagram

for traduction fron Italien, try reverso
Avevo già posto la domanda, ma non ho avuto risposta
sul piano dell'ubitx 6, ci sono come 2 transistor montati in parrallele sul piano finale
Vediamo un IRF510 e un RD15HV in parallelo.
Potrebbe essere una scelta di transistor? Si mette uno o l'altro?
Non capisco lo schema

Loris, se capisci questo, è che Reverso non funziona troppo male

cdt


Bob Lunsford
 

I just KNEW there was a logical and simple answer to this. Same item electrically but in a different "box."

Bob — KK5R

On Sunday, November 22, 2020, 6:13:09 AM EST, Raj vu2zap <rajendrakumargg@...> wrote:


Yes, you can use one or the other but not both. The pinout is different so Farhan has provided for both
solder pads.

Raj

At 22/11/2020, you wrote:
>hello,
>I had already asked the question, but I did not get an answer
>on the schematic  of ubitx 6, there are like 2 transistors mounted in parrallele on the final stage
>We see an IRF510 and a RD15HV in //.
>Maybe it’s a choice of transistor? You put one or the other?
>I don’t quite understand the diagram







Gerard
 

Bob,

Yes!!!
When my mother bought her first colour television in the '70s, I was watching through the grids. The circuit boards were the same, only the selection buttons were different. There was a price difference...for the same TV with a different brand!!!!
The salesmen didn’t like it when you knew them. Even less now when you say you have checked on the net now (Especially auto mechanics car) LOL
cdt


Evan Hand
 

Bob,
The IRF510 and RD15HVF1 can both be used in this design, but are not really electrically equal, nor are they near the same cost (if you can find the RD15HVF1 part).  For this transmitter, the RD15HVF1 would be a better part to keep the output more consistent across the bands.  

The IRF510 was designed as a high-speed high power switch.  The RD15HVF1 was designed to be used as a VHF power amp. 
The IRF510 has a higher voltage capability.
The RD15HVF1 has better gain at higher frequencies.

The BIG difference is in the price.  Doing a quick search on the internet gave an eBay price of $6.00 for the RD15HVF1 vs a Mouser price for the IRF510 of $0.98 for quantity one.

Since there are other parts of the uBITX that limit the power output at 10meters, the advantage of the higher frequency of the RD15HVF1 is negated to a large extent.  You could spend the $12+ shipping to experiment, but not really worth it to me.  It will not solve any of the earlier boards (v3, v4) purity issues so you are spending money for, at best,  a few watts at the higher end of the range.  You can get some of the frequency advantages by increasing the voltage to the finals in the uBITX with the IRF510s, the design for the RD15HVF1 is 12.5volts.  The side effect of increasing the voltage using the IRF510s is that the power goes up across all of the bands, not just the higher ones (for some this is a good thing).

Above are my interpretations of the datasheets I found and could be in error.  I just wanted to point out that they are not truly the same, just that both will work in the uBITX as designed.
As always I am happy to get any feedback or corrections so that I can continue to learn about this hobby.
73
Evan
AC9TU


Curt
 

You guys pretty much solved it. A little more backgound.
When the designer layed out the board he wanted both PA options to be supported on it. So to get both on the board he had to out both on the schematic.
When ubitx was updated, likely no changes were made to the PA.
Perhaps a note on schematic would have clarified this, but maybe a note in the designers language may not have helped many of us.

Curt


Todd Carney
 

Good background. Regarding Farhan's language, he has a better command of English than at least half the American population. All his documentation is in perfect English.


On Sun, Nov 22, 2020, 5:09 AM Curt via groups.io <wb8yyy=yahoo.com@groups.io> wrote:
You guys pretty much solved it. A little more backgound.
When the designer layed out the board he wanted both PA options to be supported on it. So to get both on the board he had to out both on the schematic.
When ubitx was updated, likely no changes were made to the PA.
Perhaps a note on schematic would have clarified this, but maybe a note in the designers language may not have helped many of us.

Curt


Todd Carney
 

The difference between "formal" pronouns and "familiar" ones is an ordinary feature of many languages: Italian is one of many including Spanish and French. Most school children in the English-speaking world are at least exposed to it.


On Sun, Nov 22, 2020, 1:08 AM IW4AJR Loris <lorisbollina@...> wrote:
Hello Todd

It is extremely difficult to translate Italian into English ...
Italian is a complex and unique language in concepts and definitions, English is too simplistic a language to express certain concepts ... 
Do you want an example: 

tu sei -> you are 
voi siete -> you are 
tu hai -> you have 
voi avete -> you have 

it is enough for you ? .... Loris


MadRadioModder
 

This is a fair assessment. There are more limitations in the pre-driver stages at higher frequencies that would limit any gains made with the RD devices.  Its better to start at Q90 and work towards the final amplifiers. 


MRM

 


On Nov 22, 2020, at 8:54 AM, Evan Hand <elhandjr@...> wrote:

Bob,
The IRF510 and RD15HVF1 can both be used in this design, but are not really electrically equal, nor are they near the same cost (if you can find the RD15HVF1 part).  For this transmitter, the RD15HVF1 would be a better part to keep the output more consistent across the bands.  

The IRF510 was designed as a high-speed high power switch.  The RD15HVF1 was designed to be used as a VHF power amp. 
The IRF510 has a higher voltage capability.
The RD15HVF1 has better gain at higher frequencies.

The BIG difference is in the price.  Doing a quick search on the internet gave an eBay price of $6.00 for the RD15HVF1 vs a Mouser price for the IRF510 of $0.98 for quantity one.

Since there are other parts of the uBITX that limit the power output at 10meters, the advantage of the higher frequency of the RD15HVF1 is negated to a large extent.  You could spend the $12+ shipping to experiment, but not really worth it to me.  It will not solve any of the earlier boards (v3, v4) purity issues so you are spending money for, at best,  a few watts at the higher end of the range.  You can get some of the frequency advantages by increasing the voltage to the finals in the uBITX with the IRF510s, the design for the RD15HVF1 is 12.5volts.  The side effect of increasing the voltage using the IRF510s is that the power goes up across all of the bands, not just the higher ones (for some this is a good thing).

Above are my interpretations of the datasheets I found and could be in error.  I just wanted to point out that they are not truly the same, just that both will work in the uBITX as designed.
As always I am happy to get any feedback or corrections so that I can continue to learn about this hobby.
73
Evan
AC9TU

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…_. _._