Re: RD16HHF1 in the uBITX

Vince Vielhaber

He might be referring to the MRFE6VP61K25H/HS. Probably seen here: http://www.eham.net/ehamforum/smf/index.php?topic=75793.0

Vince.

On 02/05/2018 01:23 AM, Jerry Gaffke via Groups.Io wrote:
Impressive.
But what's an SER?
When I google "transistor SER" all I get is a bunch of Spanish language
pages.

On Sun, Feb 4, 2018 at 09:06 pm, Leland Lannoye wrote:

Sometime ago I read about a transistor that can handle a 65:1 SER.
Do you know anything about the device?

Re: LTSpice simulation of uBitx Power Amp

John Backo

Very good, Jerry.

However, note that the output is NOT 50 ohms until AFTER the LPF.
The input to the LPF is somewhat lower. And the WA2EBY has a voltage advantage
over the 12V input to the drains, though the output of the drains is closer to 50 ohms.

So it is a bit of a misnomer to assume that the drain load is 50 ohms. This is true, incidentally,
of any AB linear amplifier (and is probably one of the sources of oscillation). I should think that the
true drain load in this configuration is closer to 10 ohms than 50 ohms. The LPF transforms it
to 50 ohms for the antenna.

But it is not unreasonable to assume an overall load of 50 ohms. But be aware though, that one of the functions of
the LPF is to produce this. It is not quite true at the drains. The actual impedance at the drains is a function
of the first capacitor/inductance stage of the LPF. Things are not quite as simple as they seem...

john

Re: LTSpice simulation of uBitx Power Amp

Jerry Gaffke

Hmmm,

I'm not assuming anything about drain loads, only that the load on the output of the transformer should be 50 ohms.
The LPF's on the uBitx and WA2EBY are symetrical, 50 ohms in and out, no impedance transformation there (at least for the fundamental).
Both amps are operating the IRF510's from a 24v supply, and the two drains of each amp
are bouncing about centered on 24vdc, out of phase.

The output should look very similar after we add in a low pass filter,
though any harmonics will be knocked out to leave behind a clean sine wave.

Jerry

On Sun, Feb 4, 2018 at 10:53 pm, John Backo wrote:
However, note that the output is NOT 50 ohms until AFTER the LPF.
The input to the LPF is somewhat lower. And the WA2EBY has a voltage advantage
over the 12V input to the drains, though the output of the drains is closer to 50 ohms.

So it is a bit of a misnomer to assume that the drain load is 50 ohms. This is true, incidentally,
of any AB linear amplifier (and is probably one of the sources of oscillation). I should think that the
true drain load in this configuration is closer to 10 ohms than 50 ohms. The LPF transforms it
to 50 ohms for the antenna.

But it is not unreasonable to assume an overall load of 50 ohms. But be aware though, that one of the functions of
the LPF is to produce this. It is not quite true at the drains. The actual impedance at the drains is a function
of the first capacitor/inductance stage of the LPF. Things are not quite as simple as they seem...

Re: RD16HHF1 in the uBITX

Alex - PA1FOX

>PA1FOX has done this, but I don't think he has

>posted detailed results yet. (He has promised
>to do so).

>I have some, but have not gotten around to finding out what
>they do. It looks very good, though.

>john

Yep, correct. I'm still here :)
View this link for the receiver in action so far.

I've been messing around with RD16HHF1 and it looks promising. Due to lack of time I have not been able to finish the tests yet, but 10 watts at 17m is easy.

They seem far more robust as well. During the test phase of the IRF's I blew up a couple of them, but the RD16HHF1 has already suffered from my experiments (wrong output impedance etc) but has survived all. The gain of the RD is much higher at the upper frequencies compared to the IRF, so I have encountered some oscillations if the bias is set too high. It's not a big problem to deal with that. The efficiency at 80m is better than with the IRF but still not so good as 30 to 17m. I'm still working on that. Need to play around with the binocular toroid.
I also still need to finish the low pass filter for 15-10m to see what it will do there. The output power at 17m gives hope for a good performance at the upper bands.

Illustrative picture so far. It's not finished yet :)
Note the double crystal filter for SSB/wide CW and narrow CW at the bottom.

73, Alex
PA1FOX

Re: RD16HHF1 in the uBITX

Lawrence Galea

On Mon, Feb 5, 2018 at 12:32 AM, Nick VK4PLN wrote:
HI Group.
I have been searching and reading topics with regards to using the RD16HHF1 in the uBITX.
So far I have only been able to find suggesstions, but no actual implementations...

I was testing my uBITX and getting 9w on 40m but only 1W at 10m...
Would love to have 5w + higher up.

Thanks.
73, Nick VK4PLN

Re: RD16HHF1 in the uBITX

K9HZ <bill@...>

Nope. Close enough.

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

email:  bill@...

On Feb 4, 2018, at 10:39 PM, Nick VK4PLN <nickpullen@...> wrote:

Excellent, thats what I am hoping to get to.
So the bias will need re-adjusting... Easy....?
What about the input and output transformers? I assume this will need modification due to the differnet impedances of the IRF and RD...

Thanks everyone for your input so far.
73.NIck VK4PLN

Re: Case

Sajeesh Pilakkat

Dear All,

Inviting you all to have a look on uBitx Case Home brewed.

http://vu3psz.blogspot.in/2018/02/ubitx-home-brewed-enclosure.html

Troubleshooting the

César EA3IAV

As others, I am facing problems regarding tx on my #ubitx
First test I did without case showed no power on meter. I did not give importance to this then as I thought it was just an old uncalibrated meter.
then everything got complicated as I made some building mistakes but after all this messing around I am in the start point: no output

i would be nice to have a troubleshooting video like on the bitx40

https://youtu.be/R8G8XAwq38A

Re: RD16HHF1 in the uBITX

K9HZ <bill@...>

Well thats a loaded question.  Reflected power just means that the transistor must dissipate the power.  So at infinity SWR, the transistor(s) must be capable of dissipating all of it.  A 50 watt output radio with 50% overall efficiency needs to dissipate 50 watts in heat (input power 100 watts). So you work the problem backwards.  If i want 25 watts out (say PA is 40 % efficient) that means the total input power is 62.5 watts and 62.5-25= 37.5 must be dissipated in heat by the PA device... but that is at perfect SWR.  If the SWR is now 3:1, then since:

At Pf = 25, Pr would be 6.25 so the device needs to dissipate at least 37.5 watts from efficiency and another 6.25 watts in reflected power or 43.75 watts.  When I design TF amps, i use design such that you can transmit into a dead short (must take full reflected) and therefore the device(s) must be capable of dissipating full input power indefinitely.

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

email:  bill@...

On Feb 4, 2018, at 11:06 PM, Leland Lannoye <wa9aoe@...> wrote:

Bill:

Sometime ago I read about a transistor that can handle a 65:1 SER. Do you know anything about the device?

Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: K9HZ <bill@...>
Date: 2/4/18 23:25 (GMT-05:00)
Subject: Re: [BITX20] RD16HHF1 in the uBITX #ubitx

Two RD16HHF1 parts replacing the 510’s will do that.

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!

email:  bill@...

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Nick VK4PLN
Sent: Sunday, February 04, 2018 10:06 PM
To: BITX20@groups.io
Subject: [SPAM] Re: [BITX20] RD16HHF1 in the uBITX #ubitx

I just wanna be able to output 5-10w on 28mhz.... not 1w... My QTH is pretty remote and without "decent" power, I wont get any contacts on >7mhz...

Might have to seriously consider an FT817, but the price.... lol.

Re: RD16HHF1 in the uBITX

K9HZ <bill@...>

BTW the BLF series was designed for this very thing.  Peak RF Voltage breakdown is also an issue.

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

email:  bill@...

On Feb 4, 2018, at 11:06 PM, Leland Lannoye <wa9aoe@...> wrote:

Bill:

Sometime ago I read about a transistor that can handle a 65:1 SER. Do you know anything about the device?

Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: K9HZ <bill@...>
Date: 2/4/18 23:25 (GMT-05:00)
Subject: Re: [BITX20] RD16HHF1 in the uBITX #ubitx

Two RD16HHF1 parts replacing the 510’s will do that.

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!

email:  bill@...

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Nick VK4PLN
Sent: Sunday, February 04, 2018 10:06 PM
To: BITX20@groups.io
Subject: [SPAM] Re: [BITX20] RD16HHF1 in the uBITX #ubitx

I just wanna be able to output 5-10w on 28mhz.... not 1w... My QTH is pretty remote and without "decent" power, I wont get any contacts on >7mhz...

Might have to seriously consider an FT817, but the price.... lol.

Re: LTSpice simulation of uBitx Power Amp

K9HZ <bill@...>

I have the .model for the RD series transistors if you care to run that too.

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

email:  bill@...

On Feb 5, 2018, at 12:21 AM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

I've now uploaded an LTSpice simulation schematic file that allows easy comparison of the uBitx and WA2EBY finals,
also a pdf version for those who have not installed LTSpice:
https://groups.io/g/BITX20/files/KE7ER/WA2EBYandUBITX.asc
https://groups.io/g/BITX20/files/KE7ER/WA2EBYandUBITX.pdf

I haven't played with it too much, haven't taken any notes.
But here's what I think I'm seeing:

The WA2EBY does perform better.
Power in is about the same between the two, power out from the WA2EBY is generally a factor of 3 greater.
The gates on the WA2EBY have nice sine waves, the uBitx is quite distorted there by capacitive loading.
Input impedance on both is about 50 ohms at 7mhz, both go down to about 12 ohms at 30mhz,
as determined by monitoring the voltage after the 50 ohm source impedance resistor.
Both show a 4x power increase when switching from 30mhz to 7mhz, more than I would
have expected on the WA2EBY, perhaps I have some wrong values on the inductors?
The IRF510 model assumes worst case for Rds(on) and Qgate, though I doubt that's just too far off.

Jerry, KE7ER

Re: LTSpice simulation of uBitx Power Amp

K9HZ <bill@...>

Dunno about that.  I always design my LP filters at 50:50 ohms in and out... and my PA transformers are 50 ohms at the output.  I don't know why you would want to make the LP filter a transform too?

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

email:  bill@...

On Feb 5, 2018, at 12:53 AM, John Backo <jabac@...> wrote:

Very good, Jerry.

However, note that the output is NOT 50 ohms until AFTER the LPF.
The input to the LPF is somewhat lower. And the WA2EBY has a voltage advantage
over the 12V input to the drains, though the output of the drains is closer to 50 ohms.

So it is a bit of a misnomer to assume that the drain load is 50 ohms. This is true, incidentally,
of any AB linear amplifier (and is probably one of the sources of oscillation). I should think that the
true drain load in this configuration is closer to 10 ohms than 50 ohms. The LPF transforms it
to 50 ohms for the antenna.

But it is not unreasonable to assume an overall load of 50 ohms. But be aware though, that one of the functions of
the LPF is to produce this. It is not quite true at the drains. The actual impedance at the drains is a function
of the first capacitor/inductance stage of the LPF. Things are not quite as simple as they seem...

john

Re: uBITX drive level..

Tilman D Thulesius

Hi
Of course "decrease" means a smaller resistance.... The original R63 is 47ohms.
I cannot find 11ohms but 10 or 12 ohms in my supply....
/ Tilman

Re: Case

Vic WA4THR

I always enjoy seeing how others have built their BitX's and thought I'd point out some ideas I used with mine that others might find useful. For example:

1. Almost everyone places their tuning control to the right, but if you place the Raduino to the right you can easily update and play with the software by just plugging in to the USB port.

2. It is hard to beat the value of the Banggood instrument case. If you turn it upside down and eliminate attaching the hard plastic feet you have a smoother mounting surface for circuit boards and can use the vent holes for a speaker grille. I added some stick-on soft plastic feet on the "new" bottom.

3. While I still want to find a nice way to attach labels to the panel, using the second line of the BitX display is a convenient place to label switches and controls.

=Vic=
WA4THR

Re: Second batch of uBITX shipping?

dj0hf

You couldn't make it up - My ubitx took just 24 hours to get from India to Germany with DHL and has now sat for 3 days (so far) at the customs in Leipzig and they are refusing to release it without a detailed description of exactly what is inside the package.
I've sent them a description and a link to the hfsignals web-site. So now it's just wait and see what happens. Maybe I'll get it eventually

Ian
DJ0HF/G3ULO

Re: Case

Jack, W8TEE

I agree:

Jack, W8TEE

From: Vic WA4THR via Groups.Io <vhklein@...>
To: BITX20@groups.io
Sent: Monday, February 5, 2018 5:58 AM
Subject: Re: [BITX20] Case

I always enjoy seeing how others have built their BitX's and thought I'd point out some ideas I used with mine that others might find useful. For example:

1. Almost everyone places their tuning control to the right, but if you place the Raduino to the right you can easily update and play with the software by just plugging in to the USB port.

2. It is hard to beat the value of the Banggood instrument case. If you turn it upside down and eliminate attaching the hard plastic feet you have a smoother mounting surface for circuit boards and can use the vent holes for a speaker grille. I added some stick-on soft plastic feet on the "new" bottom.

3. While I still want to find a nice way to attach labels to the panel, using the second line of the BitX display is a convenient place to label switches and controls.

=Vic=
WA4THR

 Virus-free. www.avast.com

Re: uBITX AGC - Adafruit TPA2016, A Success!

It’s a pretty complex device Data Sheet
i guess somebody could come up with device configuration for menu settings:
AGC fast, slow, data
That will work with the Bitx
Placed an Adafruit on order.
tnx

Re: Anyone (US Only for now) need a uBITX Raduino repaired?

John Kemker

Hopefully, I won't need your service, Jim, but it's great to hear that you're willing to provide it!
--

73 de W5NNH

Re: uBITX AGC - Adafruit TPA2016, A Success!

Art Olson

Nick

Did u post some code or did I miss your posting

73
Art -N2AJO

On Feb 5, 2018, at 9:11 AM, rwhinric@... wrote:

It’s a pretty complex device Data Sheet
i guess somebody could come up with device configuration for menu settings:
AGC fast, slow, data
That will work with the Bitx
Placed an Adafruit on order.
tnx

Re: Case

pat griffin

Me too

Pat AA4PG

http://www.cahabatechnology.com

From: BITX20@groups.io <BITX20@groups.io> on behalf of Jack Purdum via Groups.Io <jjpurdum@...>
Sent: Monday, February 5, 2018 7:24:03 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Case

I agree:

Jack, W8TEE

From: Vic WA4THR via Groups.Io <vhklein@...>
To: BITX20@groups.io
Sent: Monday, February 5, 2018 5:58 AM
Subject: Re: [BITX20] Case

I always enjoy seeing how others have built their BitX's and thought I'd point out some ideas I used with mine that others might find useful. For example:

1. Almost everyone places their tuning control to the right, but if you place the Raduino to the right you can easily update and play with the software by just plugging in to the USB port.

2. It is hard to beat the value of the Banggood instrument case. If you turn it upside down and eliminate attaching the hard plastic feet you have a smoother mounting surface for circuit boards and can use the vent holes for a speaker grille. I added some stick-on soft plastic feet on the "new" bottom.

3. While I still want to find a nice way to attach labels to the panel, using the second line of the BitX display is a convenient place to label switches and controls.

=Vic=
WA4THR

 Virus-free. www.avast.com