开云体育

ctrl + shift + ? for shortcuts
© 2025 开云体育
  1. BITX20
  2. Messages
Expanded Topics Messages Polls
Date
Re: BITX40- tune button- no output

 

Steve, you need to install?the TX-RX mod so that the radio will go into TX when you press the button.



Alternatively, you can press PTT manually on the mic and then press the tune button.

73 Allard PE1NWL

Re: BITX40- tune button- no output

 

Thanks Mike, but according to ,?

CONNECTING A STRAIGHT MORSE KEY or 'TUNE' BUTTON:

A straight key (or external electronic keyer) can be connected to Raduino pin A1 (connector P1, brown wire). It is recommended to install a 1K series resistor to protect the Arduino input. When the key is up (open) pin A1 will be HIGH. When the key is down (closed, shorted to ground) pin A1 will be LOW, and a carrier will be transmitted.

You could also wire up a simple push button instead of connecting a morse key. The generated CW carrier can be used for tuning up your antenna. In that case please note that you will be transmitting a carrier at full duty cycle, therefore don't keep the tune button pressed for too long to prevent overheating the final!

Am I misunderstanding something here?? Aloha, Steve
Re: BITX40- tune button- no output

 

Tune button? ? There is no tune button with Allard’s mods!? Maybe you are thinking of the CW spot / fine tune button?? This puts a tone on cw for allowing you to align the incoming signal with the CW offset and it also enables fine tune on the dial with 1 Hz steps.? Holding it down at the same time as the function button will lock the tune dial.

Parallel up a button with the straight key down and this will give you a momentary Tune button.

73 Mike ZL1AXG


On Fri, 16 Feb 2018 at 8:36 PM, Steve Thatcher <stevep2p@...> wrote:
Hi gang.? I've got my '40 assembled, tested, and mounted in a box.? Loaded Allard's latest as well as all his hardware mods, with the exception of the TX-RX mod.? 6W output on SSB, but no output on CW when I push the tune button.? I get the sidetone on the speaker, but no movement on the wattmeter.? Something in the Settings Menu?? Any ideas?? I've searched the messages, but no joy.? Thanks, Aloha, Steve WH6ST

BITX40: Allard's Firmware with Rotary Encoder?

 

Hello All,

I got Allard's Raduino sketch to compile on an Uno R3 that I'm playing with, and I also got a rotary encoder working on a test sketch, and now I need to figure out how to make Allard's sketch use the rotary encoder. I'm pretty new to Arduino (this is my first actual project aside from Blink and a few basic tests). I've figured out how to convert to an I2C display- that's easy enough, and I have a version of the sketch that does that successfully. I must be humble and admit that I don't have the time I wish I did, and I'd be better off if someone already figured out the encoder part so I could get a jump on that. I have other mods that I want to do, but Allard's code is so well featured I'd?like to start there, if possible.

Thanks for the assist and 73!
--
Ryan Flowers - W7RLF
BITX40- tune button- no output

 

Hi gang.? I've got my '40 assembled, tested, and mounted in a box.? Loaded Allard's latest as well as all his hardware mods, with the exception of the TX-RX mod.? 6W output on SSB, but no output on CW when I push the tune button.? I get the sidetone on the speaker, but no movement on the wattmeter.? Something in the Settings Menu?? Any ideas?? I've searched the messages, but no joy.? Thanks, Aloha, Steve WH6ST
Re: RD16HHF1 in the uBITX #ubitx

John
 

Hello Marco,

Yes? I saw this cap on some schematics and they are supposed to flatten the gain curve.

Thanks for the suggestion.

I will have a look at this when I am finished with the audio side.

73, John (VK2ETA)
Re: RD16HHF1 in the uBITX #ubitx

M Garza
 

John,
Have you tried putting a 150 to 330pf cap across pins 1 & 6 on T11?? It might help balance the output.? Most push-pull amps have this cap.

Just a suggestion.

Marco - KG5PRT?

On Feb 15, 2018 7:39 AM, "John" <passionfruit88@...> wrote:
I have done a strait replacement of the IRF510s with RD16HHF1s.?
?
Here are the before and after values I got.
?
All tests done with uBitx VR1 drive level in the same position of approx 60% of range.
?
1. IRF510s and main board at 12.1V. PA idle current checked at 0.20A total (factory setting) so assume 100mA in each final.?
(For info, Rx currents: 164mA no volume, about 209mA "normal" volume).?
- At 7.1Mhz:? ?10W, total current: 1.79A, of which PA current: 1.31A, therefore main board current 0.48A
- At 14.2Mhz: 5.5W, total current: 1.39A, of which PA current: 1.0A,? therefore main board current 0.39A
- At 21.2Mhz: 2.2W, total current: 0.95A, of which PA current: 0.53A, therefore main board current 0.42A
- At 28.1Mhz: 1.3W, total current: 0.95A, of which PA current: 0.53A, therefore main board current 0.42A
?
?
2. IRF510s with 16.5V, 13.8V for main board. PA total idle current checked at 0.21A.?
(For info, Rx currents: 188mA no volume, about 230mA "normal" volume).?
- At 7.1Mhz:? 19W, total current: 2.65A, of which PA current: 2.09A, therefore main board current 0.56A
- At 14.2Mhz: 11W, total current: 2.20A, of which PA current: 1.80A, therefore main board current 0.40A
- At 21.2Mhz: 5.5W, total current: 1.40A, of which PA current: 1.00A, therefore main board current 0.40A
- At 28.1Mhz: 2.2W, total current: 1.02A, of which PA current: 0.60A, therefore main board current 0.42A
?
?
I haven't found a definitive reference for the safe and optimum values of the RD16HHF1s idle bias current but it seems to range from 200 to 500mA. So I would not recommend long term usage of the 500mA bias I used for these measurements.
I will reset mine to probably the 400-450mA value I read from some articles.
?
3. RD16HHF1s and main board at 12.1VDC, 250mA idle bias each (Total 0.5A PA idle current).?
- At 7.1Mhz:? 10W,? PA current: 1.20A
- At 14.2Mhz: 9W,? ?PA current: 1.21A
- At 21.2Mhz: 4.5W, PA current: 0.65A
- At 28.1Mhz: 5.5W, PA current: 0.95A
?
?
4. RD16HHF1s and main board at 12.1VDC, 500mA idle bias each (Total 1A PA idle current).?
- At 7.1Mhz: 10W, PA current: 1.18A
- At 14.2Mhz: 9W, PA current: 1.26A
- At 21.2Mhz: 5W, PA current: 0.71A
- At 28.1Mhz: 6W, PA current: 1.11A
?
?
5. RD16HHF1s and main board at 13.8VDC, 500mA idle bias each (Total 1A PA idle current).?
- At 7.1Mhz:? 13.5W, PA current: 1.95A
- At 14.2Mhz: 13.5W, PA current: 1.93A
- At 21.2Mhz: 6W,? ? PA current: 1.38A
- At 28.1Mhz: 9.5W,? PA current: 1.79A
?
?
?
Interesting observations:
?
A. The RD16HHF1 produces a much flatter power curver over frequency (in my device), although it shows a dip somewhere near the 15m band.
?
B. The IRF510 can produce some nice power in the lower frequencies when increasing the PA supply voltage, but it comes at the price of a steep power drop at higher frequencies.
?
C. The bias does not seem to influence the efficiency of the finals at full power with RD16HHF1, since biasing at 250 and 500mA produces essentially the same output for the same DC power input. Assuming distortion reduces with higher bias, can we assume a higher bias (within limits) is preferable? Any risk of thermal runaway?
?
D. The board main current (which includes the current in the driving stages of the power amplifier) does not seem to change with frequency from 20m onwards. Is this because the gain is pretty constant? If so, most of the drop in power with increasing frequency seems to be in the IRF510s, supporting the results obtained with the RD16HHF1s.
?
E. With the current uBitx PA circuit the RD16HHF1 seems limited in output, although not having the proper test equipment I can't say where the limitation occurs.
?
F. When I increased the drive through VR1 I noticed that at around 40% for the lower frequencies and at around 60% for the top frequencies I get a compression effect and the output does not increase much more from there on. I left it at 60% and got a positive feedback on the voice quality on my first QSO on 40m. Therefore I assume that the compression/clipping is not significant at that level (but I can't measure the sprectral purity).
?
?
So since my target was around 10W on 10m and 10 to 15W on 40m minimum I can say I have reached my goal just by changing the finals to RD16HHF1s and supplying the board with 13.8VDC (below the 15.2/15V stated in the respective datasheets of the RD16HHF1 and TDA2822).
?
To replace the finals I simply cut the legs of the IRF510s about 3mm above the board and correspondingly cut and crossed over the drain and source pins of the RD16s to match, then soldered in place.
?
It would be interesting to compare these results with others who performed the finals swap on the stock uBitx.
?
Next is the installation of the TPA2016 audio amplifier with I2C controllable AGC.

This is a lot of fun.
?
All the best,
?
73, John (VK2ETA)
?
Re: uBitx LCD Viewing Angle and Replacement Hints Needed

Mike Lichtman
 

Thank you to those who responded to my question. Bill Richardson’s informing me of the contrast control on the back of the
VFO module did the trick. It was originally set to maximum. Now that the green display is toned down and functional, i will probably
stay with it. Maybe in the future I will consider the blue/white or black /white displays. 73 Mike KF6KXG
Re: RD16HHF1 in the uBITX #ubitx

 

Rlacement of MOSfets alone can't not solve the case.

?However there is reasonable improvement,. Interestingly, there is a dip in gain at 21.2MHz and recovered at 28 MHz. Twe need to analyse this behaviour. I wonder what would happen if we can tweak C261 and C262? by lowering their values , say 68nF instead of 100nF !!? ??
If R97 and R98 could be increased to say 100 ohms, the gate loading would reduce, I agree that, we? need to ensure thast amplifier would not become unstable.

regards
?sarma
?vu3zmv

?
Re: BITX QSO Afternoon/Night, Sunday, February 18, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere

 

开云体育

>> “This is a worldwide event for BITX40 stations starting at 7pm in each time zone. To participate, call CQ BITX on Sunday, starting at?3PM and/or 7PM?your local time”

?

So this goes on for more than 28 hours then?

?

?

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:

Like us on Facebook!

?

Moderator – North American QRO Yahoo Group.

?

email:? bill@...

?

?

From: [email protected] [mailto:[email protected]] On Behalf Of John P
Sent: Thursday, February 15, 2018 9:09 PM
To: [email protected]
Subject: [BITX20] BITX QSO Afternoon/Night, Sunday, February 18, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere

?

BITX QSO Afternoon/Evening, Sunday, February 18, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Join us as we make contacts from BITX40 to BITX40 on 7.277 MHz in 40 meters!

This is a worldwide event for BITX40 stations starting at 7pm in each time zone. To participate, call CQ BITX on Sunday, starting at?3PM and/or 7PM?your local time. The BITX QSO Night continues through the evening and conditions usually improve after sunset, so it is worthwhile to participate later in the evening.

Suggested Best Operating Practices:

Work at QRP power levels unless conditions require more power.
Call and listen for CQ BITX on the hour and every quarter hour.
It is helpful if you call CQ BITX with your callsign, name and location.?
Repeat your callsign a number of times during your CQ BITX and during QSO's.
Start a QSO by confirming the callsign, location, name and signal report of the other operator.
Say the callsign, name and location of the other operator so others can hear.
If the frequency is busy, avoid long conversations.
After your initial QSO is complete, ask if there are any other stations who would like to contact.

Report your QSO's, discuss propagation, noise, signal reports, audio reports, antenna type, etc. in this thread.

This is an undirected, scheduled event.? The BITX QSO Night relies on you to call CQ BITX to initiate contacts with other stations, so warm up that final and transmit a few calls on Sunday evening.? Talk to you then!
--
John - WA2FZW


Virus-free.

BITX QSO Afternoon/Night, Sunday, February 18, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere

John P
 

BITX QSO Afternoon/Evening, Sunday, February 18, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Join us as we make contacts from BITX40 to BITX40 on 7.277 MHz in 40 meters!

This is a worldwide event for BITX40 stations starting at 7pm in each time zone. To participate, call CQ BITX on Sunday, starting at?3PM and/or 7PM?your local time. The BITX QSO Night continues through the evening and conditions usually improve after sunset, so it is worthwhile to participate later in the evening.

Suggested Best Operating Practices:

Work at QRP power levels unless conditions require more power.
Call and listen for CQ BITX on the hour and every quarter hour.
It is helpful if you call CQ BITX with your callsign, name and location.?
Repeat your callsign a number of times during your CQ BITX and during QSO's.
Start a QSO by confirming the callsign, location, name and signal report of the other operator.
Say the callsign, name and location of the other operator so others can hear.
If the frequency is busy, avoid long conversations.
After your initial QSO is complete, ask if there are any other stations who would like to contact.

Report your QSO's, discuss propagation, noise, signal reports, audio reports, antenna type, etc. in this thread.

This is an undirected, scheduled event.? The BITX QSO Night relies on you to call CQ BITX to initiate contacts with other stations, so warm up that final and transmit a few calls on Sunday evening.? Talk to you then!
--
John - WA2FZW
Re: RD16HHF1 in the uBITX #ubitx

 

The same would be true for the RD16Hxxx devices, incidentally.

john
AD5YE
Re: RD16HHF1 in the uBITX #ubitx

 

Indeed, there is the PA+ supply voltage on the IRF510 drains during receive.
But zero drain current because the IRF510 gate voltage is zero
and nowhere else for the PA+ supply to go.? Not so much as a bias or feedback resistor.

So those IRF510 FET's are already doing the job of the extra FET that you had proposed.

Jerry


On Thu, Feb 15, 2018 at 05:40 pm, Arv Evans wrote:
But that does not remove DC from the finals.? I did not notice that the bias was dumped during receive.? That is my error.??
?
Re: RD16HHF1 in the uBITX #ubitx

 

开云体育

Jerry

But that does not remove DC from the finals.? I did not notice that the bias was dumped during receive.? That is my error.??

Arv
_-_




Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: "Jerry Gaffke via Groups.Io" <jgaffke@...>
Date: 2/15/18 5:16 PM (GMT-07:00)
Subject: Re: [BITX20] RD16HHF1 in the uBITX #ubitx

In the case of the uBitx and Bitx40 we use the IRF510 FET's to turn off
the PA power by shutting down the gate bias voltage source during receive.
Drain current should be zero.

On Thu, Feb 15, 2018 at 02:43 pm, Arv Evans wrote:
For power conservation it is possible to use a power FET to turn OFF voltage
to the RF PA section during receive mode.? Turn the switch device on with
+TX power and off when this goes to ground.? I used an IRF510 because
I have some spares.
?
Re: RD16HHF1 in the uBITX #ubitx

 

I believe it has already been done for you.
The LM78L05 regulator that supplies 5v to the IRF510 gate bias pots is in turn powered form the TX 12v rail.
That TX rail is shut down during receive by the TR relay, goes to zero volts, so gate bias will also do so.


On Thu, Feb 15, 2018 at 04:53 pm, John Backo wrote:
I think Jerry has a much simpler idea -- just
find a way to disconnect the gate bias during receive.
Re: RD16HHF1 in the uBITX #ubitx

 

I think Jerry has a much simpler idea -- just
find a way to disconnect the gate bias during receive.
This would put the gates at 0v, and effectively shut off
the IRF510 drains. Probably a good idea.

It might work, but I wonder about the sudden increase and decrease
of voltage on the gates. it might precipitate oscillation or action in the
non-linear area of operation. The linear area we are using is quite
narrow and a bit unstable.

Probably it would work fine for most, but not so good for a few. It depends on the
actual device in use.

john
AD5YE
Re: RD16HHF1 in the uBITX #ubitx

 

开云体育

Like this:

?

?

?

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:

Like us on Facebook!

?

Moderator – North American QRO Yahoo Group.

?

email:? bill@...

?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Arv Evans
Sent: Thursday, February 15, 2018 4:43 PM
To: [email protected]
Subject: Re: [BITX20] RD16HHF1 in the uBITX #ubitx

?

Hello

For power conservation it is possible to use a power FET to turn OFF voltage
to the RF PA section during receive mode.? Turn the switch device on with
+TX power and off when this goes to ground.? I used an IRF510 because

I have some spares.

?

Arv
_._

?

On Thu, Feb 15, 2018 at 3:26 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

The FET's are more linear with a high quiescent current.
Though the WA2EBY gets away with 10ma quiescent drain currents into the IRF510's
which is a considerably less linear device than the RD16HHF1's.
If planning on portable use, I'd definitely try something less than 500ma.

On Thu, Feb 15, 2018 at 01:20 pm, John wrote:

I will then leave the idle PA current near 500mA per device despite the current drain.

?


Virus-free.

Re: RD16HHF1 in the uBITX #ubitx

 

In the case of the uBitx and Bitx40 we use the IRF510 FET's to turn off
the PA power by shutting down the gate bias voltage source during receive.
Drain current should be zero.


On Thu, Feb 15, 2018 at 02:43 pm, Arv Evans wrote:
For power conservation it is possible to use a power FET to turn OFF voltage
to the RF PA section during receive mode.? Turn the switch device on with
+TX power and off when this goes to ground.? I used an IRF510 because
I have some spares.
?
Re: Advice on selling Bitx40 on EBay

 

?Post it here or on FB if you accept Paypal.? I bought a uBitx off a fellow ham that was in the same boat.?

73, Michael
KM4OLT
Re: RD16HHF1 in the uBITX #ubitx

 

Hello

For power conservation it is possible to use a power FET to turn OFF voltage
to the RF PA section during receive mode.? Turn the switch device on with
+TX power and off when this goes to ground.? I used an IRF510 because
I have some spares.

Arv
_._


On Thu, Feb 15, 2018 at 3:26 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
The FET's are more linear with a high quiescent current.
Though the WA2EBY gets away with 10ma quiescent drain currents into the IRF510's
which is a considerably less linear device than the RD16HHF1's.
If planning on portable use, I'd definitely try something less than 500ma.

On Thu, Feb 15, 2018 at 01:20 pm, John wrote:
I will then leave the idle PA current near 500mA per device despite the current drain.
73721 - 73740 of 115539