interested also in the progress of the control board for the amplifiers.
Hi all, havent seen any talk lately. Just wondering how it was going with the 100watt amp kit/testing?
? Regards
?73, ?John ?KE2AMP
|
Hi all, havent seen any talk lately. Just wondering how it was going with the 100watt amp kit/testing?
? Regards
?73, ?John ?KE2AMP
|
Digital RF Attenuator - PE4302 and PE4312
Bill, I use the PE4312 to control the TX Drive in my 2022 SDR Transceiver. The implementation was per the , including the 10K resistors in the C16 and Data lines: "A 10 kΩ resistor on the inputs to pin 1 and 3 (see Figure 26) will eliminate package resonance between the RF input pin and the two digital inputs." I operate the PE4312 in direct parallel programming mode similar to your 64-dB RF Attenuator Board. The performance was erratic and I couldn't always achieve maximum attenuation. In the course of researching this problem, I came across . The application note is titled " Replacing PE4302 with PE4312" and includes the following statements:
- The Peregrine PE4312 is a pin-compatible upgraded version of the PE4302 with higher linearity, improved attenuation accuracy and faster switching speed. Although it was designed to be pin-for-pin compatible with PE4302 there are some subtle differences that should be considered when using PE4312 as a direct replacement.
- The PE4302 application circuit contained two resistors in the C16 and DATA lines....The PE4312 does not need resistors on the C16 or the DATA line and it is preferable to remove them or reduce the values so the logic threshold levels are met.
The second point above from the Application Note is in direct contradiction with the PE4312 Datasheet. Replacing the 10K Ohm resistors with 100 Ohm resistors solved my problem. The need for the 10K Ohm resistors with the PE4312 was touched on briefly in an older thread, however, it appears leaving them in with the PE4312 may lead to erratic behavior. Anyone substituting PE4312 for PE4302 in your 64-dB RF Attenuator Board should be aware of this. 73, Rod, AD5GH
|
Re: uBITX not T-41: Inversion of t/r signal
Ya das is richtig! ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of Siegfried Jackstien Sent: Thursday, October 19, 2023 3:07 PM To: [email protected]Subject: Re: [AmateurRadioBuilders] uBITX not T-41: Inversion of t/r signal ? nope .. the trigger from the rig (positive 3 to 12v) is the power supply in this case never seen an "open collector" output?? (any ptt circuit pulling to ground does this) dg9bfc sigi Am 19.10.2023 um 21:43 schrieb jean-marie via groups.io: I think there is an error in the drawing . No powersupply Here is what I’m using in the T41.? It’s good to 250V and 2amps. ? 
? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? ? On Thu, Oct 19, 2023 at 09:25 AM, Mark Hatch wrote: The last item on my hardware TODO list is to provide a remote signal to trigger an amp or a RF switch. The signal that I need to expose is the T/R signal. The problem is that it goes positive on TX and grounds on RX. Sort of the opposite of what external devices expect.
Hi Mark,
Here is an inverting switch that I use on my TeensyMaestro project to key my rig.? This assumes keying a positive line by bringing it to ground.? This can be just about any NPN switching transistor.? I used a 2N3904 because I had some on hand.? Because this is inverting, it might work for you as-is.? If the polarity (HIGH vs LOW) is incorrect, you can use another GPIO pin (if you have a free one available) that is set the opposite of the existing RX/TX pin.???A better choice than my switching transistor would be an opto-isolator.? I believe it would be set up in a very similar way.
If you are out of GPIO pins, you could stack another transistor ahead of this one to invert the signal.? You would need a + V (3.5 or 5) through a current limiting resistor to the collector of the other transistor.
Any of you engineers see a flaw in what I am telling Mark?
73, Len, KD0RC ?
|
Re: uBITX not T-41: Inversion of t/r signal
nope .. the trigger from the rig (positive 3 to 12v) is the power
supply in this case
never seen an "open collector" output?? (any ptt circuit pulling
to ground does this)
dg9bfc sigi
Am 19.10.2023 um 21:43 schrieb
jean-marie via groups.io:
toggle quoted message
Show quoted text
I think there is an error in the
drawing . No powersupply
Met vriendelijke groeten
Jean-Marie
Here
is what I’m using in the T41.? It’s good to 250V and
2amps.
?
?
?
Dr.
William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ
PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ
?
Owner
- Operator
Big
Signal Ranch – K9ZC
Staunton,
Illinois
?
Owner
– Operator
Villa
Grand Piton – J68HZ
Soufriere,
St. Lucia W.I.
Rent
it:
?
Moderator:
North American QRO Group at Groups.IO.
Moderator:
Amateur Radio Builders Group at Groups.IO.
?
email:?
bill@...
?
?
?
On Thu, Oct 19, 2023 at 09:25 AM,
Mark Hatch wrote:
The last item on my hardware TODO
list is to provide a remote signal to trigger an amp
or a RF switch. The signal that I need to expose is
the T/R signal. The problem is that it goes positive
on TX and grounds on RX. Sort of the opposite of what
external devices expect.
Hi Mark,
Here is an inverting switch that I use on my
TeensyMaestro project to key my rig.? This assumes
keying a positive line by bringing it to ground.? This
can be just about any NPN switching transistor.? I used
a 2N3904 because I had some on hand.? Because this is
inverting, it might work for you as-is.? If the polarity
(HIGH vs LOW) is incorrect, you can use another GPIO pin
(if you have a free one available) that is set the
opposite of the existing RX/TX pin.???A better choice
than my switching transistor would be an opto-isolator.?
I believe it would be set up in a very similar way.
If you are out of GPIO pins, you could stack another
transistor ahead of this one to invert the signal.? You
would need a + V (3.5 or 5) through a current limiting
resistor to the collector of the other transistor.
Any of you engineers see a flaw in what I am telling
Mark?
73, Len, KD0RC
|
Re: uBITX not T-41: Inversion of t/r signal
What do you need a power supply for? ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of jean-marie via groups.io Sent: Thursday, October 19, 2023 2:44 PM To: AmateurRadioBuilders < [email protected]> Subject: Re: [AmateurRadioBuilders] uBITX not T-41: Inversion of t/r signal ? I think there is an error in the drawing . No powersupply Here is what I’m using in the T41.? It’s good to 250V and 2amps. ? 
? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? ? On Thu, Oct 19, 2023 at 09:25 AM, Mark Hatch wrote: The last item on my hardware TODO list is to provide a remote signal to trigger an amp or a RF switch. The signal that I need to expose is the T/R signal. The problem is that it goes positive on TX and grounds on RX. Sort of the opposite of what external devices expect.
Hi Mark,
Here is an inverting switch that I use on my TeensyMaestro project to key my rig.? This assumes keying a positive line by bringing it to ground.? This can be just about any NPN switching transistor.? I used a 2N3904 because I had some on hand.? Because this is inverting, it might work for you as-is.? If the polarity (HIGH vs LOW) is incorrect, you can use another GPIO pin (if you have a free one available) that is set the opposite of the existing RX/TX pin.???A better choice than my switching transistor would be an opto-isolator.? I believe it would be set up in a very similar way.
If you are out of GPIO pins, you could stack another transistor ahead of this one to invert the signal.? You would need a + V (3.5 or 5) through a current limiting resistor to the collector of the other transistor.
Any of you engineers see a flaw in what I am telling Mark?
73, Len, KD0RC ?
|
Re: uBITX not T-41: Inversion of t/r signal
I think there is an error in the drawing . No powersupply
Met vriendelijke groeten Jean-Marie Www.on7en.be
Here is what I’m using in the T41.? It’s good to 250V and 2amps. ? 
? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? ? On Thu, Oct 19, 2023 at 09:25 AM, Mark Hatch wrote: The last item on my hardware TODO list is to provide a remote signal to trigger an amp or a RF switch. The signal that I need to expose is the T/R signal. The problem is that it goes positive on TX and grounds on RX. Sort of the opposite of what external devices expect.
Hi Mark,
Here is an inverting switch that I use on my TeensyMaestro project to key my rig.? This assumes keying a positive line by bringing it to ground.? This can be just about any NPN switching transistor.? I used a 2N3904 because I had some on hand.? Because this is inverting, it might work for you as-is.? If the polarity (HIGH vs LOW) is incorrect, you can use another GPIO pin (if you have a free one available) that is set the opposite of the existing RX/TX pin.???A better choice than my switching transistor would be an opto-isolator.? I believe it would be set up in a very similar way.
If you are out of GPIO pins, you could stack another transistor ahead of this one to invert the signal.? You would need a + V (3.5 or 5) through a current limiting resistor to the collector of the other transistor.
Any of you engineers see a flaw in what I am telling Mark?
73, Len, KD0RC
|
Re: uBITX not T-41: Inversion of t/r signal
No… drive the gate of the IRFI630 and its inverse… I shudda put that on the schematic too… ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ?
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Show quoted text
From: [email protected] < [email protected]> On Behalf Of jerry-KF6VB Sent: Thursday, October 19, 2023 2:39 PM To: [email protected]Cc: K9HZ <bill@...> Subject: Re: [AmateurRadioBuilders] uBITX not T-41: Inversion of t/r signal ? On 2023-10-19 12:14, K9HZ wrote: Here is what I’m using in the T41. It’s good to 250V and 2amps.
** But only positive, right?
- Jerry, KF6VB
DR. WILLIAM J. SCHMIDT - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ VP2EHZ
Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois
Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: [1]
Moderator: North American QRO Group at Groups.IO.
Moderator: Amateur Radio Builders Group at Groups.IO.
email: bill@...
FROM: [email protected] <[email protected]>
ON BEHALF OF Len, KD0RC
SENT: Thursday, October 19, 2023 11:02 AM
TO: [email protected]
SUBJECT: Re: [AmateurRadioBuilders] uBITX not T-41: Inversion of t/r
signal
On Thu, Oct 19, 2023 at 09:25 AM, Mark Hatch wrote:
The last item on my hardware TODO list is to provide a remote signal
to trigger an amp or a RF switch. The signal that I need to expose
is the T/R signal. The problem is that it goes positive on TX and
grounds on RX. Sort of the opposite of what external devices expect.
Hi Mark,
Here is an inverting switch that I use on my TeensyMaestro project to
key my rig. This assumes keying a positive line by bringing it to
ground. This can be just about any NPN switching transistor. I used
a 2N3904 because I had some on hand. Because this is inverting, it
might work for you as-is. If the polarity (HIGH vs LOW) is incorrect,
you can use another GPIO pin (if you have a free one available) that
is set the opposite of the existing RX/TX pin. A better choice than
my switching transistor would be an opto-isolator. I believe it would
be set up in a very similar way.
If you are out of GPIO pins, you could stack another transistor ahead
of this one to invert the signal. You would need a + V (3.5 or 5)
through a current limiting resistor to the collector of the other
transistor.
Any of you engineers see a flaw in what I am telling Mark?
73, Len, KD0RC
Links:
------
[1]
[2] /g/AmateurRadioBuilders/message/2602
[3] /mt/102062267/243852
[4] /g/AmateurRadioBuilders/post
[5] /g/AmateurRadioBuilders/editsub/243852
[6]
/g/AmateurRadioBuilders/leave/11522011/243852/920863695/xyzzy
|
Re: uBITX not T-41: Inversion of t/r signal
On 2023-10-19 12:14, K9HZ wrote: Here is what I’m using in the T41. It’s good to 250V and 2amps. ** But only positive, right? - Jerry, KF6VB
DR. WILLIAM J. SCHMIDT - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ VP2EHZ
Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois
Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com [1]
Moderator: North American QRO Group at Groups.IO.
Moderator: Amateur Radio Builders Group at Groups.IO.
email: bill@...
FROM: [email protected] <[email protected]>
ON BEHALF OF Len, KD0RC
SENT: Thursday, October 19, 2023 11:02 AM
TO: [email protected]
SUBJECT: Re: [AmateurRadioBuilders] uBITX not T-41: Inversion of t/r
signal
On Thu, Oct 19, 2023 at 09:25 AM, Mark Hatch wrote:
The last item on my hardware TODO list is to provide a remote signal
to trigger an amp or a RF switch. The signal that I need to expose
is the T/R signal. The problem is that it goes positive on TX and
grounds on RX. Sort of the opposite of what external devices expect. Hi Mark,
Here is an inverting switch that I use on my TeensyMaestro project to
key my rig. This assumes keying a positive line by bringing it to
ground. This can be just about any NPN switching transistor. I used
a 2N3904 because I had some on hand. Because this is inverting, it
might work for you as-is. If the polarity (HIGH vs LOW) is incorrect,
you can use another GPIO pin (if you have a free one available) that
is set the opposite of the existing RX/TX pin. A better choice than
my switching transistor would be an opto-isolator. I believe it would
be set up in a very similar way.
If you are out of GPIO pins, you could stack another transistor ahead
of this one to invert the signal. You would need a + V (3.5 or 5)
through a current limiting resistor to the collector of the other
transistor.
Any of you engineers see a flaw in what I am telling Mark?
73, Len, KD0RC
Links:
------
[1]
[2] /g/AmateurRadioBuilders/message/2602
[3] /mt/102062267/243852
[4] /g/AmateurRadioBuilders/post
[5] /g/AmateurRadioBuilders/editsub/243852
[6]
/g/AmateurRadioBuilders/leave/11522011/243852/920863695/xyzzy
|
Re: uBITX not T-41: Inversion of t/r signal
Here is what I’m using in the T41.? It’s good to 250V and 2amps. ? 
? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of Len, KD0RC Sent: Thursday, October 19, 2023 11:02 AM To: [email protected]Subject: Re: [AmateurRadioBuilders] uBITX not T-41: Inversion of t/r signal ? On Thu, Oct 19, 2023 at 09:25 AM, Mark Hatch wrote: The last item on my hardware TODO list is to provide a remote signal to trigger an amp or a RF switch. The signal that I need to expose is the T/R signal. The problem is that it goes positive on TX and grounds on RX. Sort of the opposite of what external devices expect.
Hi Mark,
Here is an inverting switch that I use on my TeensyMaestro project to key my rig.? This assumes keying a positive line by bringing it to ground.? This can be just about any NPN switching transistor.? I used a 2N3904 because I had some on hand.? Because this is inverting, it might work for you as-is.? If the polarity (HIGH vs LOW) is incorrect, you can use another GPIO pin (if you have a free one available) that is set the opposite of the existing RX/TX pin.???A better choice than my switching transistor would be an opto-isolator.? I believe it would be set up in a very similar way.
If you are out of GPIO pins, you could stack another transistor ahead of this one to invert the signal.? You would need a + V (3.5 or 5) through a current limiting resistor to the collector of the other transistor.
Any of you engineers see a flaw in what I am telling Mark?
73, Len, KD0RC
|
Re: uBITX not T-41: Inversion of t/r signal
Thanks all!?
Since I am trying to continue supporting the Nano (very criptled because of flash size), I don't have an extra GPIO pins. So will use the transistor with a current limiting to do the inversion. Will initially breadboard it with some jumpers to existing design to get it right and then put it on board on the next design.
This has been a real fun project for me because it involved both software (port of the existing KD8CEC software) and board design (with KICAD). I have already gone thru multiple board revisions and now have designs that work with the v3-v5 Raduino mechanicals as well as the v6 Raduino dimesions too. To date I have been hand assembling all the SMT components (yes, that includes the wonderful si5351...). On the next run to JCLPCB I will have them place the SMT components and then offer some beta boards at cost. Not looking to make money here, if the designs prove out, hopefully someone else will take that ball. Currently have boards for Teensy 4, 4.1, Pico, Ardruino IOT, BLE and RP Connect. I don't like the cost-performance of the Arduinos chips, so will probably focus on the Teensy and Pico going forward. The Pico W with the second processor that can be used for wifi seems to be interesting...
As one might expect, porting the KD8CEC code to these platforms has been challenging. Most of the math assumed integers were 16 bits... Spent a lot of time tracking all those down. But in addition, had to deal with? the more subtle assumptions about the Nano (e.g. timing! I wonder why that delay is there...).?
Everything works pretty good, so this first phase seems close to being done. (Well having said that, tracking down a few new problems that occurred when I went to the latest IDE, library and board versions....)
Again, thanks all!
73
Mark
|
Re: uBITX not T-41: Inversion of t/r signal
WRT switching negative/positive:
Here's a link to the manual for that keyer. The schematic is on page
21. The PTT circuitry
is just a pair of 2n7000 MOSFETs.
The keyer is cased in a plastic box. I'm not sure if that circuit will
work with something that
needs a common ground with the linear.
- Jerry, KF6VB
|
Re: uBITX not T-41: Inversion of t/r signal
Hello Mark,
Inversion of the signal is simple - it can be done with a single NPN
transistor and one resistor. Your output turns on the transistor, and
the
resistor limits the base current.
It gets more complicated if you want to also drive linears that have
a *negative* relay voltage. Most tube linears are like that.
One solution would be to use a high voltage opto-isolator with jumpers
to select whether you expect to switch a negative or positive voltage.
Or to
have two output connectors, one for each polarity.
I recently bought a CW keyer kit that had a really elegant circuit at
the output with a couple of MOSFETs that can switch positive or negative
- same
output connector, no jumpers, no fuss no muss.
I have a couple of the TSW Raduino cards. These have a Teensy 4.1.
One is
in my UBITX, and I adapted the other one for a control card in a
homebrew solid state linear.
- Jerry, KF6VB
toggle quoted message
Show quoted text
On 2023-10-19 08:25, Mark Hatch wrote: I am working on a series of new uBITX Raduino boards that support
newer MCU's like Teensy, PICO, and the upper end of the Arduino nano
family. As part of this I have ported the KD8CEC firmware to these new
board designs. All this is on my github:
The last item on my hardware TODO list is to provide a remote signal
to trigger an amp or a RF switch. The signal that I need to expose is
the T/R signal. The problem is that it goes positive on TX and grounds
on RX. Sort of the opposite of what external devices expect.
I am looking for a simple and small SMT based solution for this. Tried
the obvious googling, but hope you understand I am more a software guy
than a hardware so don't understand all the tradeoffs when dealing
with RF. I know this sounds like a high school student looking for
someone to do his homework ;-) , but perhaps someone can provide a
pointer?
Thanks!
73
Mark
AJ6CU/7
Links:
------
[1] /g/AmateurRadioBuilders/message/2595
[2] /mt/102062267/243852
[3] /g/AmateurRadioBuilders/post
[4] /g/AmateurRadioBuilders/editsub/243852
[5]
/g/AmateurRadioBuilders/leave/11522011/243852/920863695/xyzzy
|
Re: uBITX not T-41: Inversion of t/r signal
On Thu, Oct 19, 2023 at 09:25 AM, Mark Hatch wrote:
The last item on my hardware TODO list is to provide a remote signal to trigger an amp or a RF switch. The signal that I need to expose is the T/R signal. The problem is that it goes positive on TX and grounds on RX. Sort of the opposite of what external devices expect.
Hi Mark, Here is an inverting switch that I use on my TeensyMaestro project to key my rig.? This assumes keying a positive line by bringing it to ground.? This can be just about any NPN switching transistor.? I used a 2N3904 because I had some on hand.? Because this is inverting, it might work for you as-is.? If the polarity (HIGH vs LOW) is incorrect, you can use another GPIO pin (if you have a free one available) that is set the opposite of the existing RX/TX pin.???A better choice than my switching transistor would be an opto-isolator.? I believe it would be set up in a very similar way. If you are out of GPIO pins, you could stack another transistor ahead of this one to invert the signal.? You would need a + V (3.5 or 5) through a current limiting resistor to the collector of the other transistor.   Any of you engineers see a flaw in what I am telling Mark? 73, Len, KD0RC
|
Re: uBITX not T-41: Inversion of t/r signal
Hello Mark,
Good initiative.? I am interested to know the objective of porting into Teensy and Pico. Though bit contrast Teensy is expensive than Pico. I made a usdx during covid times, the audio TX is bit metallic. Is there any improvement of any sort if achieved ...please do share.?
73, Probir VU2BQF?
On Thu, 19 Oct, 2023, 8:55 pm Mark Hatch, < mark2382@...> wrote: I am working on a series of new uBITX Raduino boards that support newer MCU's like Teensy, PICO, and the upper end of the Arduino nano family. As part of this I have ported the KD8CEC firmware to these new board designs. All this is on my github:
The last item on my hardware TODO list is to provide a remote signal to trigger an amp or a RF switch. The signal that I need to expose is the T/R signal. The problem is that it goes positive on TX and grounds on RX. Sort of the opposite of what external devices expect.
I am looking for a simple and small SMT based solution for this. Tried the obvious googling, but hope you understand I am more a software guy than a hardware so don't understand all the tradeoffs when dealing with RF. I know this sounds like a high school student looking for someone to do his homework ;-) , but perhaps someone can provide a pointer?
Thanks!
73
Mark
AJ6CU/7
|
Re: uBITX not T-41: Inversion of t/r signal
Hi Mark… welcome aboard.? ? No need to reinvent the wheel… there are plenty of commercial radios doing this already.? I’d just? plagiarize the circuit out of the K3… it works really well for me! ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of Mark Hatch Sent: Thursday, October 19, 2023 10:25 AM To: [email protected]Subject: [AmateurRadioBuilders] uBITX not T-41: Inversion of t/r signal ? I am working on a series of new uBITX Raduino boards that support newer MCU's like Teensy, PICO, and the upper end of the Arduino nano family. As part of this I have ported the KD8CEC firmware to these new board designs. All this is on my github:https://github.com/aj6cu
The last item on my hardware TODO list is to provide a remote signal to trigger an amp or a RF switch. The signal that I need to expose is the T/R signal. The problem is that it goes positive on TX and grounds on RX. Sort of the opposite of what external devices expect.
I am looking for a simple and small SMT based solution for this. Tried the obvious googling, but hope you understand I am more a software guy than a hardware so don't understand all the tradeoffs when dealing with RF. I know this sounds like a high school student looking for someone to do his homework ;-) , but perhaps someone can provide a pointer?
Thanks!
73
Mark
AJ6CU/7
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uBITX not T-41: Inversion of t/r signal
I am working on a series of new uBITX Raduino boards that support newer MCU's like Teensy, PICO, and the upper end of the Arduino nano family. As part of this I have ported the KD8CEC firmware to these new board designs. All this is on my github:https://github.com/aj6cu
The last item on my hardware TODO list is to provide a remote signal to trigger an amp or a RF switch. The signal that I need to expose is the T/R signal. The problem is that it goes positive on TX and grounds on RX. Sort of the opposite of what external devices expect.
I am looking for a simple and small SMT based solution for this. Tried the obvious googling, but hope you understand I am more a software guy than a hardware so don't understand all the tradeoffs when dealing with RF. I know this sounds like a high school student looking for someone to do his homework ;-) , but perhaps someone can provide a pointer?
Thanks!
73
Mark
AJ6CU/7
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Re: File /K9HZ 20W 1-54 MHz RF Amplifier module/20W AMP 160M-6M Troubleshooting Guide V1.00 101523.pdf uploaded
#file-notice
Thanks Lou.? I’ve had two people in the last month tell me that they had faulty connectors on the coax they used at the output of the amp (not the surface mount but the one on the coax)… and they got warm to hot from pro-longed operation.? I’ll make a future video of me WELDING sheet metal with this thing.? It really is pretty much bullet-proof. ? The troubleshooting document is short and covers some of the common mistakes and expected voltages.? I probably missed some obvious things so if there are others that want to contribute to it… please send me your updates. ? Glenn… I took your advice and added a pad for capacitors (albeit stacked) right at the output transformer (T3) center tap to ground.? Doesn’t make a difference at low frequency, but does at higher frequency. ? ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ?
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From: [email protected] < [email protected]> On Behalf Of Lou, KI5FTY Sent: Monday, October 16, 2023 10:21 AM To: [email protected]Subject: Re: [AmateurRadioBuilders] File /K9HZ 20W 1-54 MHz RF Amplifier module/20W AMP 160M-6M Troubleshooting Guide V1.00 101523.pdf uploaded #file-notice ? Bill, thanks?for this, very helpful ? The following files and folders have been uploaded to the Files area of the [email protected] group. By: K9HZ <bill@...> Description:
K9HZ 20W 160-6M Amp Troubleshooting Guide V1.00 101523
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Re: File /K9HZ 20W 1-54 MHz RF Amplifier module/20W AMP 160M-6M Troubleshooting Guide V1.00 101523.pdf uploaded
#file-notice
Bill, thanks?for this, very helpful
The following files and folders have been uploaded to the Files area of the [email protected] group.
By: K9HZ <bill@...>
Description:
K9HZ 20W 160-6M Amp Troubleshooting Guide V1.00 101523
|
File /K9HZ 20W 1-54 MHz RF Amplifier module/20W AMP 160M-6M Troubleshooting Guide V1.00 101523.pdf uploaded
#file-notice
The following files and folders have been uploaded to the Files area of the [email protected] group.
By: K9HZ <bill@...>
Description:
K9HZ 20W 160-6M Amp Troubleshooting Guide V1.00 101523
|
K9HZ
Len, KD0RC