Hi Bob,
FT4 and FT8 are each constant envelope signals with just one signal at a time (one"tone") in the FT4 or FT8 bandwidth. They are purely single-tone FSK signals, and as such there is no reason why they cannnot be passed through a class C amplifier, since there is no "amplitude" content to contend with. Just think of "SSB" mode as the lowest frequency IF in your transceiver chain and FT4 or FT8 are sequential single tones in the full SSB bandwidth. Note that this is not true for modes like PSK31 and QPSK family of protocols, because they DO have an amplitude variation component.
Kindest regards,
Kai, KE4PT

On 7/27/2021 15:14, alanbh@... wrote:

The answer would be NO.  FT8 and FT4 is a tone modulate SSB type signal.  You cannot put an SSB or modulated signal through class C amplifier without distorting the signal. The maximum class you can put a modulated of SSB type signal through without or absolute minimal distortion is a class B Amplifier. 

73, alan WA3EKL

----- Original Message -----
From: "Bob McGraw - K4TAX" <rmcgraw@...>
To: WSJTX@groups.io
Sent: Tuesday, July 27, 2021 7:05:24 PM
Subject: [WSJTX] Class C Amplifier Application #transmit


I've not seen any clear or definitive answer to the question "can one 
suddessfully run FT-8/4 or other WSJT-X modes via a Class C solid state 
VHF amplifier?"  Asking because I have a VHF amplifier which is not linear.

73

Bob, K4TAX

Bill:

>> Let us know if the Avast whitelisting helps with the issue please?

1. Every time I created the path C:\Users\harry\AppData\Local\Temp\WSJT-X\... "WSJT-X" was deleted from ...\Temp\...
2. I forced the path C:/Users/harry/AppData/Local/TempWSJT-X/ into Avast even though it underlined it in red.
3. I (also) shutdown WSPR, rebooted my computer, power cycled my radio, and restarted WSPR.
4. So far (18 hours) I have had no errors.  Normally I would have had about 200 stacked on top of each other.
5. A few minutes ago, I checked the path C:\Users\harry\AppData\Local\Temp\WSJT-X\ and observed "WSJT-X" was deleted from  ...\Local\Temp\
6. The Status File Error seems to be gone for now but whitelisting the path seems not to have any affect on the error going away.  I suspect the reboot and WSPR restart cleared the Status File Error.

harry

On 7/26/2021 17:31, Bill Somerville wrote:

Hi Harry,

it is Windows shells like CMD that are picky about path directory separators, the underlying file system accepts both, nothing to do with the Windows kernel. They are normally accepted in shells and applications when quoted. Anyway, it is of little matter and you can switch to what you call Windows path directory separators.

Let us know if the Avast whitelisting helps with the issue please?

73
Bill
G4WJS.

On 26/07/2021 22:13, harry wrote:

Bill:

Thanks for the quick reply.

>> MS Windows allows both types.

Including (old) Windows 7?  When you say "allow" I presume Windows converts "/" to "\" in path names (in the kernel I hope).

>> Make sure the full path to the file is whitelisted in your AV

My anti-virus program is Avast.  Avast whitelist will not accept UNIX path separators (as displayed in the WSJT-X  diagnostic).  I did whitelist the path with Windows separators.  I will see what happens.

73

harry

KN4IJY

My On 7/26/2021 16:23, Bill Somerville wrote:

On 26/07/2021 21:06, harry wrote:

I am a new group member but a multi year WSPR user.  I just installed the latest WSJT-X software for Windows7.  At various times for unknown reasons I get the following error:

As one can see, the diagnostic path separators are "/" which is the UNIX style.  The Windows7 path separator is "\".  Is the Status File Error caused by WSPR trying to open an invalid path in Windows or an error in the diagnostic text?  I never got this error in earlier WSPR versions.

KN4IJY

Hi Harry,

the path directory separators in the message are fine, MS Windows allows both types.

This error is usually caused by interference from anti-virus applications. Make sure the full path to the file is whitelisted in your AV exclusions.

73
Bill
G4WJS.

The answer would be NO.  FT8 and FT4 is a tone modulate SSB type signal.  You cannot put an SSB or modulated signal through class C amplifier without distorting the signal. The maximum class you can put a modulated of SSB type signal through without or absolute minimal distortion is a class B Amplifier. 

73, alan WA3EKL

----- Original Message -----
From: "Bob McGraw - K4TAX" <rmcgraw@...>
To: WSJTX@groups.io
Sent: Tuesday, July 27, 2021 7:05:24 PM
Subject: [WSJTX] Class C Amplifier Application #transmit


I've not seen any clear or definitive answer to the question "can one 
suddessfully run FT-8/4 or other WSJT-X modes via a Class C solid state 
VHF amplifier?"  Asking because I have a VHF amplifier which is not linear.

73

Bob, K4TAX

Hi Harry,

OK, perhaps Avast is not so helpful with whitelisting temporary files and directories. WSJT-X creates a temporary directory "%LocalAppData%\Temp\WSJT-X\" into which it stores various temporary files while a session is running, the directory is deleted when WSJT-X exits. I would like to think that Avast would allow you to whitelist that directory and anything contained in it, even when it does not exist at the time the exception is created. TBH I would prefer that AV products did not interfere in other applications at all!

73
Bill
G4WJS.

On 28/07/2021 16:00, harry wrote:

Bill:

>> Let us know if the Avast whitelisting helps with the issue please?

1. Every time I created the path C:\Users\harry\AppData\Local\Temp\WSJT-X\... "WSJT-X" was deleted from ...\Temp\...
2. I forced the path C:/Users/harry/AppData/Local/TempWSJT-X/ into Avast even though it underlined it in red.
3. I (also) shutdown WSPR, rebooted my computer, power cycled my radio, and restarted WSPR.
4. So far (18 hours) I have had no errors.  Normally I would have had about 200 stacked on top of each other.
5. A few minutes ago, I checked the path C:\Users\harry\AppData\Local\Temp\WSJT-X\ and observed "WSJT-X" was deleted from  ...\Local\Temp\
6. The Status File Error seems to be gone for now but whitelisting the path seems not to have any affect on the error going away.  I suspect the reboot and WSPR restart cleared the Status File Error.

harry

On 7/26/2021 17:31, Bill Somerville wrote:

Hi Harry,

it is Windows shells like CMD that are picky about path directory separators, the underlying file system accepts both, nothing to do with the Windows kernel. They are normally accepted in shells and applications when quoted. Anyway, it is of little matter and you can switch to what you call Windows path directory separators.

Let us know if the Avast whitelisting helps with the issue please?

73
Bill
G4WJS.

On 26/07/2021 22:13, harry wrote:

Bill:

Thanks for the quick reply.

>> MS Windows allows both types.

Including (old) Windows 7?  When you say "allow" I presume Windows converts "/" to "\" in path names (in the kernel I hope).

>> Make sure the full path to the file is whitelisted in your AV

My anti-virus program is Avast.  Avast whitelist will not accept UNIX path separators (as displayed in the WSJT-X  diagnostic).  I did whitelist the path with Windows separators.  I will see what happens.

73

harry

KN4IJY

My On 7/26/2021 16:23, Bill Somerville wrote:

On 26/07/2021 21:06, harry wrote:

I am a new group member but a multi year WSPR user.  I just installed the latest WSJT-X software for Windows7.  At various times for unknown reasons I get the following error:

As one can see, the diagnostic path separators are "/" which is the UNIX style.  The Windows7 path separator is "\".  Is the Status File Error caused by WSPR trying to open an invalid path in Windows or an error in the diagnostic text?  I never got this error in earlier WSPR versions.

KN4IJY

Hi Harry,

the path directory separators in the message are fine, MS Windows allows both types.

This error is usually caused by interference from anti-virus applications. Make sure the full path to the file is whitelisted in your AV exclusions.

73
Bill
G4WJS.

On Jul 28, 2021, at 10:11 AM, Peter Hall, VK6HP <p.hall@...> wrote:

run WSJT-X with the SDR since it gives you a sensitive display of artifacts, and lists any secondary decodes and their relative strength

Bill:

>> Let us know if the Avast whitelisting helps with the issue please?

1. Every time I created the path C:\Users\harry\AppData\Local\Temp\WSJT-X\... "WSJT-X" was deleted from ...\Temp\...
2. I forced the path C:/Users/harry/AppData/Local/TempWSJT-X/ into Avast even though it underlined it in red.
3. I (also) shutdown WSPR, rebooted my computer, power cycled my radio, and restarted WSPR.
4. So far (18 hours) I have had no errors.  Normally I would have had about 200 stacked on top of each other.
5. A few minutes ago, I checked the path C:\Users\harry\AppData\Local\Temp\WSJT-X\ and observed "WSJT-X" was deleted from  ...\Local\Temp\
6. The Status File Error seems to be gone for now but whitelisting the path seems not to have any affect on the error going away.  I suspect the reboot and WSPR restart cleared the Status File Error.

harry

On 7/26/2021 17:31, Bill Somerville wrote:

Hi Harry,

it is Windows shells like CMD that are picky about path directory separators, the underlying file system accepts both, nothing to do with the Windows kernel. They are normally accepted in shells and applications when quoted. Anyway, it is of little matter and you can switch to what you call Windows path directory separators.

Let us know if the Avast whitelisting helps with the issue please?

73
Bill
G4WJS.

On 26/07/2021 22:13, harry wrote:

Bill:

Thanks for the quick reply.

>> MS Windows allows both types.

Including (old) Windows 7?  When you say "allow" I presume Windows converts "/" to "\" in path names (in the kernel I hope).

>> Make sure the full path to the file is whitelisted in your AV

My anti-virus program is Avast.  Avast whitelist will not accept UNIX path separators (as displayed in the WSJT-X  diagnostic).  I did whitelist the path with Windows separators.  I will see what happens.

73

harry

KN4IJY

My On 7/26/2021 16:23, Bill Somerville wrote:

On 26/07/2021 21:06, harry wrote:

I am a new group member but a multi year WSPR user.  I just installed the latest WSJT-X software for Windows7.  At various times for unknown reasons I get the following error:

As one can see, the diagnostic path separators are "/" which is the UNIX style.  The Windows7 path separator is "\".  Is the Status File Error caused by WSPR trying to open an invalid path in Windows or an error in the diagnostic text?  I never got this error in earlier WSPR versions.

KN4IJY

Hi Harry,

the path directory separators in the message are fine, MS Windows allows both types.

This error is usually caused by interference from anti-virus applications. Make sure the full path to the file is whitelisted in your AV exclusions.

73
Bill
G4WJS.

Bill:

>> Let us know if the Avast whitelisting helps with the issue please?

1. Every time I created the path C:\Users\harry\AppData\Local\Temp\WSJT-X\... "WSJT-X" was deleted from ...\Temp\...
2. I forced the path C:/Users/harry/AppData/Local/TempWSJT-X/ into Avast even though it underlined it in red.
3. I (also) shutdown WSPR, rebooted my computer, power cycled my radio, and restarted WSPR.
4. So far (18 hours) I have had no errors.  Normally I would have had about 200 stacked on top of each other.
5. A few minutes ago, I checked the path C:\Users\harry\AppData\Local\Temp\WSJT-X\ and observed "WSJT-X" was deleted from  ...\Local\Temp\
6. The Status File Error seems to be gone for now but whitelisting the path seems not to have any affect on the error going away.  I suspect the reboot and WSPR restart cleared the Status File Error.

harry

On 7/26/2021 17:31, Bill Somerville wrote:

Hi Harry,

it is Windows shells like CMD that are picky about path directory separators, the underlying file system accepts both, nothing to do with the Windows kernel. They are normally accepted in shells and applications when quoted. Anyway, it is of little matter and you can switch to what you call Windows path directory separators.

Let us know if the Avast whitelisting helps with the issue please?

73
Bill
G4WJS.

On 26/07/2021 22:13, harry wrote:

Bill:

Thanks for the quick reply.

>> MS Windows allows both types.

Including (old) Windows 7?  When you say "allow" I presume Windows converts "/" to "\" in path names (in the kernel I hope).

>> Make sure the full path to the file is whitelisted in your AV

My anti-virus program is Avast.  Avast whitelist will not accept UNIX path separators (as displayed in the WSJT-X  diagnostic).  I did whitelist the path with Windows separators.  I will see what happens.

73

harry

KN4IJY

My On 7/26/2021 16:23, Bill Somerville wrote:

On 26/07/2021 21:06, harry wrote:

I am a new group member but a multi year WSPR user.  I just installed the latest WSJT-X software for Windows7.  At various times for unknown reasons I get the following error:

As one can see, the diagnostic path separators are "/" which is the UNIX style.  The Windows7 path separator is "\".  Is the Status File Error caused by WSPR trying to open an invalid path in Windows or an error in the diagnostic text?  I never got this error in earlier WSPR versions.

KN4IJY

Hi Harry,

the path directory separators in the message are fine, MS Windows allows both types.

This error is usually caused by interference from anti-virus applications. Make sure the full path to the file is whitelisted in your AV exclusions.

73
Bill
G4WJS.

Willie,

Looking at narrowband, high resolution spectra from SDRuno, HDSDR etc. is a good start and is useful for identifying gross effects.  However, I find it's very useful to go the next step and actually run WSJT-X with the SDR since it gives you a sensitive display of artifacts, and lists any secondary decodes and their relative strengths.  Apart from drive level issues (including audio harmonics), things such as hum show up readily on the display and, in cases where the modulation bandwidth is preserved, as spurious decodes.  Hum, for example, is often offset from the wanted carrier by power-grid related frequencies.

As I mentioned in an earlier post, for quality checks I use the SDRPlay RSPdx and SDRuno running on an old Windows laptop, with the virtual CAT and audio connections made by VSPE and Virtual Audio Cable, respectively.  Both connection programs are free for basic applications.  This system runs simultaneously with whatever transmit system is under test.  Most often the transmitter chain is connected to a dummy load but sometimes short, discreet on-air antenna tests produce interesting results - such as the 630 m passive intermodulation distortion I referred to earlier.

In all monitoring systems you do have to work hard at keeping the level to the monitoring receiver adequate, but not excessive.  Terminating the receiver input is a good place to start experimenting.

73, Peter.

Hi Harry,

it is Windows shells like CMD that are picky about path directory separators, the underlying file system accepts both, nothing to do with the Windows kernel. They are normally accepted in shells and applications when quoted. Anyway, it is of little matter and you can switch to what you call Windows path directory separators.

Let us know if the Avast whitelisting helps with the issue please?

73
Bill
G4WJS.

On 26/07/2021 22:13, harry wrote:

Bill:

Thanks for the quick reply.

>> MS Windows allows both types.

Including (old) Windows 7?  When you say "allow" I presume Windows converts "/" to "\" in path names (in the kernel I hope).

>> Make sure the full path to the file is whitelisted in your AV

My anti-virus program is Avast.  Avast whitelist will not accept UNIX path separators (as displayed in the WSJT-X  diagnostic).  I did whitelist the path with Windows separators.  I will see what happens.

73

harry

KN4IJY

My On 7/26/2021 16:23, Bill Somerville wrote:

On 26/07/2021 21:06, harry wrote:

I am a new group member but a multi year WSPR user.  I just installed the latest WSJT-X software for Windows7.  At various times for unknown reasons I get the following error:

As one can see, the diagnostic path separators are "/" which is the UNIX style.  The Windows7 path separator is "\".  Is the Status File Error caused by WSPR trying to open an invalid path in Windows or an error in the diagnostic text?  I never got this error in earlier WSPR versions.

KN4IJY

Hi Harry,

the path directory separators in the message are fine, MS Windows allows both types.

This error is usually caused by interference from anti-virus applications. Make sure the full path to the file is whitelisted in your AV exclusions.

73
Bill
G4WJS.