Frequently Asked Questions


What operating systems does PSKMETER require?

PSKMETER is a 32-bit Windows application that will run on any Windows operating system after Windows 3.1. That means it will run on Windows 95, 98, 2000, NT, XP, ME, and so on. The program will run on a Mac if you are running a Windows emulator (like Power PC).

I'm still not clear on the USB operation. How does that work?

PSKMETER is designed to operate as a serial device, to be connected to a com port using the standard RS-232 cable. However, most station computers are already using their comports to control their rigs via an interface such as RigBlaster, NOMIC, etc, and not everyone will have a spare com port available. There are two solutions we can offer: First, if you are running Windows 2000, Windows NT, or Windows XP we supply a little driver that will allow you to operate the PSKMETER and your rig interface on the same com port. You will have to make up a "Y" RS232 cable that plugs into your computer on one side and into your rig interface and PSKMETER on the other. The diagram for the cable can be found in the kit assembly instructions. Second, if you would rather use a USB port, you can purchase the optional Serial-to-USB cable. This is an active cable that plugs into the PSKMETER on one side, and into your computer's USB port on the other. We give you a driver to install that will create a virtual comport, that talks through the USB port. For instance, if you already have COM1 and COM2, after you install this driver you will have a COM3, but that's really using a USB port.

What is the length of your "Serial to USB" adapter cable? If I added a 6' extension would I have any problems signal strength wise?

The adapter cable is about 5 feet in length. You can add quite a long serial cable to this with absolutely no problem.

I have a DB- 9 and a 1/2" chassis punch, but for some reason never thought about using them on plastic. Is there anything to watch out for when doing this?

The optional enclosure is plastic. The material is not brittle or thin, and drilling and punching are quite easy and the holes come out cleanly.

Is PSKMETER compatible with the Rigblaster Plus?

It sure is. PSKMETER is compatible with all known rig interfaces to your computer. The reason is that PSKMETER plugs directly into your computer and does not know about your rig interace or even your PSK31 software. Therefore, there are no compatibility problems.

How does the RF signal "T" to PSKMETER?

The PSKMETER is a high input impedance device, and not a 50 ohm load. Therefore, you should never terminate the output of your transmitter directly into PSKMETER. This would not be good for PSKMETER, and the reflected power would not be good for your transmitter's final amplifier. Instead, run a short length of 50 ohm coax cable from your transmitter to one side of a BNC "T". Plug the T into the PSKMETER, and then plug the other side of the T into the feedline that runs to your antenna. This way the PSKMETER merely sits on the feedline and can sample the RF voltage as the signal goes out to the antenna. IMPORTANT: Do NOT run a "stub" cable from your transmitter to the PSKMETER. That will result in a very dramatic degradation of your system's SWR!

Do I use the connections to the Rigblaster as I am using now?

No, PSKMETER has three connections: One goes to a 9-12 volt power source, one goes to your computer's serial or USB port, and one goes to your feedline. There is no interface to a Rigblaster, or any other rig interface.

Can I order the kit pre-assembled?

The kit takes about 30 minutes for a person with average kit building skill to assemble, and a little bit longer if this is your first kit. Therefore, in most cases it is not a burden to receive PSKMETER in kit form (in fact, most people enjoy the building experience). However in some cases where the operator has poor vision or cannot keep steady hands we do consider pre-assembling the kit. In such cases, please send us email before placing your order.

Does PSKMETER work on all PSK31 bands?

Yes, it does. The PowerPoint presentation uses the 20 meter band as an example in the computation of the low pass filter cutoff frequency and component values. However, this result is non-critical and the circuit will work just as well on all the other bands.

What is the current version of PSKMETER?

There are 4 version numbers associated with PSKMETER. The current version of each are:
Hardware (the PSKMETER board): 2.0
Firmware (embedded software on the board): 1.10
Software (pskmeter.exe):
Assembly and User's Manual: 1.8

How can I determine the version of PSKMETER I currently have?

To find out the current version of your hardware, look at the silkscreen on the printed circuit board below the crystal and microprocessor chip. The version number will be printed in the format "(Rev x.x mm/yy)." To determine the firmware version, run pskmeter.exe and go to Help|About. The firmware version number, and the software version number will be displayed in the About dialog.

What is the impact be of leaving either the PSKmeter hardware or the PSKmeter software active while using other modes (such as AFSK, FSK RTTY, MFSK, CW, etc.)?

You can leave the PSKMeter connected to your transceiver and computer and be running other modes with no adverse effects by unchecking the Automatic Level Control (in the right mouse click menu). The software will not be able to syncronize to the 31 Hz signal it expects and therefore the display will not be useful. By disabling the Automatic Level Control feature, you are insuring that PSKMETER will not occassionally modify your sound card settings. The best approach is to just terminate the PSKMETER application when not running PSK31. Future versions of PSKMETER will allow you to disable the display when in non-PSK modes.

Can I damage anything in my shack by feeding PSKMETER a signal which is different from the expected PSK31 signal?

No. The PSKMETER has a front-end zener that protects the ADC and microprocessor from over-voltages, preventing damage to the PSKMETER. Since the meter is just a monitor, you cannot damage your transceiver. Similarly, the Windows software controls only the output level of your sound card and cannot damage your computer, its files, the sound card, or your transceiver.

What kind of power adapter can I use to power PSKMETER?

The meter gets regulated power from an onboard 78L05 +5 volt regulator. The input to this regulator needs to be from a minimum of +7 volts and can go all the way up to +35 volts. The regulator can supply 100 ma, but the current drain for this circuit is far below that. So, just about any power adapter with a center pin positive DC voltage is going to work just fine. Be careful however to not put a negative voltage on the center pin, or AC. The 7805 is not protected and will definitely emit smoke if a negative voltage is applied to it!

Another interesting point about power adapters. A noisy adapter, or one with lots of ripple, will cause strange analog voltage problems that prevent the meter from working properly. If you suspect your power adapter is causing problem, just try using a 9-volt battery. If PSKMeter starts working correctly, you know your wall wart needs replacement.

The meter shows its copyright notice and version number in hyperterm, but the pskmeter.exe application reports that the meter is not responding. What am I doing wrong?

If you are running XP, there was a bug in pskmeter.exe that was corrected in version 1.4. Check the version of pskmeter you are running. If it is prior to 1.4, download a fresh copy. This problem will be solved.

If you are running pskmeter.exe version 1.4, and still have a communication problem, then read on:
On some computers the implementation of the serial ports requires hardware flow control. The pskmeter printed circuit board version 1.0 (shown on the silkscreen) did not account for this. You can easily patch the board to solve the problem. Solder a short wire from the solder pad of pin 4 of the DB9 connector to the solder pad of pin 6 of the connector. You can identify these pins very easily. Pin 4 is on the component side of the board, second pad away from the marking "J3 COMP". Pin 6 is on the solder side of the board, first pad on the right as you hold the board so that the DB9 connector is at the top of the board.

If you have printed circuit board version 1.1, you will need to make the same patch, but because there is a plated through-hole for pin 4 that connects to pin 9, you can just solder a short wire from pin 9 to pin 6 (i.e., the first pad on the left to the right pad on the right, on the solder side of the board).

Versions 1.2 and higher will have this patch built into the pcb.

Will the pskmeter have any effect on SWR?

The pskmeter is a high input impedance device on all amateur bands, relative to a 50 ohm load. It should therefore have no measureable effect on SWR. It is good practice to check the SWR after you have assembled the meter and connected to your transceiver and feedline, provided you have not connected the pskmeter using a stub length of coax going from the female center connector of the BNC T to the pskmeter. Any such short length of coax is going to have an adverse effect on SWR. Instead, be sure that the BNC T is plugged directly into the pskmeter. If you still notice any effect on SWR, do the following:

Start with a 50 ohm dummy load connected to the T on one end and your transceiver on the other, and leave the pskmeter out entirely. Verify that the SWR is 1.0 or close to it. If not, check your cables, connectors, etc. Now add the pskmeter to the T. Verify that the SWR does not change. When you get to this point, you should be able to swap the dummy load out and put in your antenna and repeat the test. The pskmeter should have no effect on SWR.

PSKMETER works beautifully with the AUTO mode off. When I turn the AUTO mode on, the audio level bounces around and doesn't settle to a stable value. What's the fix for this?

There are several distinct possibilities to explore:
1. Your Feedback Gain setting is too high. When the gain is too high you have the classic situation of a system with an overdriven feedback loop resulting in oscillations. Right click on the PSKMeter window to obtain the menu, and go to Feedback Gain option. Reduce the gain until the oscillations disappear and the audio level is stable.


2. Your transmitter's ALC is turned on. If ALC is on, you have two devices trying to deal with the audio level. PSKMETER will be adjusting the audio level for an optimum PSK signal, but your radio will be adjusting its gain also, and so the two devices are at odds with one another. Consequently the audio level will be unstable (and unsatisfactory). Be sure to turn ALC off, speech processing off, DSP off, and so forth. If your transmitter's ALC cannot be turned off (as for example the TenTec Pegasus), your options are to use a different radio, or to operate with AUTO disabled.

3. Your rig's microphone gain is too high. If you display the sound card mixer you will see that pskmeter is attempting to lower the audio level to the 1% or lower level. That's because the volume output of your sound card is too much for your transceiver's mic input and as a result tiny changes in the audio level create huge changes in the rf output. Hence, pskmeter finds it difficult to impossible to fine tune the audio level to get to the "sweet spot" in the feedback loop.

The solution is to turn down the microphone gain of your transceiver, making it less sensitive to audio input. PSKMeter will then turn up the audio level into the linear range. In fact, a good procedure would be as follows:

1. Open the sound card mixer, so you can see the audio control sliders.

2. Send a PSK31 idle signal into a dummy load, so you can see the pskmeter wave form, the audio level in percent, and then allow pskmeter to adjust the signal.

3. You will see that pskmeter eventually attempts to set the audio levels to the 1% level, so the sliders (both master and wave out) are near the bottom of their travel.
4. Now turn down your rig's microphone gain. Assuming it was set to 100%, cut it in half to 50%.

5. Now manually move the two sliders to their mid-range position. pskmeter will detect a strong signal and will probably attempt to cut it back. But the important point is this: pskmeter will find good signal at higher audio levels than before--the percentage will be higher than 1% (maybe 5 or 10%), and the sliders will ride a little higher.

6. If you get this far, you can really tune the system up. Run the microphone gain down all the way. Set the sliders manually to their mid positions. Pskmeter will report an audio level of 25% (1/2 x 1/2).

7. Now start turning up the microphone gain slowly (remember, pskmeter is sampling at most 2 times per second). At some point, pskmeter will find the audio levels to be too high (you will get the SPLATTER message), and pskmeter is going to start lowering the sliders. At that point, just back off on your microphone gain a bit. You are done! The sliders are in their mid-range, and that enables pskmeter to make all the adjustments it needs in the future.

8. From that point on, you never have to fool with this adjustment again. Make a note of your microphone gain setting , in case you have to go back to this setting. From here on out pskmeter has all the resources and control it needs to give ideal feedback.

AUTO mode is enabled, but the audio level is not being controlled. What's wrong?

Check the Feedback Gain menu option for the gain being set to zero. In early versions of pskmeter.exe, a zero value of gain was allowed, which resulted in the inability of the meter to change the audio level. New versions of pskemeter.exe limit the lowest value of gain to 0.1.

Communication between the computer and the PSKMETER seems to be erratic. What's the problem?

One way to confirm this is to feed your rig's output into a dummy load instead of an antenna. If you observe that all these problems with the PSKMETER disappear, you have a problem with either RF leaking into your computer, or reflected RF from your antenna coming down the coax ground braid. There are several things you can do to clean up your RF environment:

1. Add 3 or 4 loops in the coax at the antenna end of your feedline.
2. Put toroids onto all the cables attached to your computer, including the audio cables, serial cables, even the keyboard, mouse and power cables. This is just good practice for any PSK31 station.
3. Check your grounding. For example, make sure that your computer's ground is the same as your transceiver's ground (i.e., connect the coax ground to the computer ground).
4. If all else fails, try using a grounded metal enclosure for your meter (or wrapping copper tape around the plastic enclosure, being sure you spot solder the seams and ground the copper).

Before leaving this subject, there is another potential reason PSKMeter can behave erratically. One user reports his findings this way:

"I finally got my PSKMETER to work and it works like a charm. After much frustration I finally found the problem. This might be useful for you if someone else has a similar problem. It sort of worked giving some responses but not the signal graph or “no signal” text and Hyper Terminal never found it. Well, it was the wall wart which looked like it was putting out 13 VDC but must have too much ripple. It works perfectly on a 9 volt battery."

Therefore, if you suspect your power adapter, try using a 9 volt battery. If that cures the problem, you need to replace your wall wart.

Does the USB converter cause any conflicts with existing USB devices like printers or scanners?

The USB converter and its special driver does not create conflicts or cause any problems whatsoever with either other USB devices or other serial ports.

Sometimes the green oscilloscope display disappears. Is there a patch for that?

This problem was resolved in version 1.4.3 of pskmeter.exe. Just download the latest version of the software and copy over the existing version on your computer.

Is PSKMeter available for Linux?

The pskmeter application software has been ported to the Linux platform by Martin Ewing, AA6E. You can download a copy of from Since this is third-party software for the PSKMeter hardware, we cannot offer support.

What if I can't solder the crystal case to ground?

The assembly insructions recommend if possible to solder the crystal case to ground. In some cases we ship crystals that have a plastic film around it, leaving only the top of the case exposed, and therefore not convenient to connect to the ground pad provided on the printed circuit board. In this instance, it is not necessary to ground the case. PSKMeter will work perfectly well without it.

Can I use a 9 volt battery instead of a wall wart?

PSKMeter draws 12.8 ma when idling, and 2.9 ma during transmit. A 9 volt alkaline battery is usually rated at 25 ma continuous with an operating life of 625 mAh. Therefore a single 9 V battery can be expected to power the PSKMeter for about 48 hrs. A 5% duty cycle would increase the operating time by 5% for all practical purposes. In practical terms, a single 9V battery would probably make it through Field Day, especially if the PSKMeter was turned off/disconnected when it was not in use.

Is there a problem if I want to use COM port 10 (or higher)?

Prior to version of, pskmeter.exe was able to communicate on COM ports 1 through 9, but not on COM port 10 or higher. This was fixed in version which allows connection to any COM port.

I lost the mini-CD with the Serial-to-USB drivers. Is there a way I can download from your site?

There sure is. 

You may have received the BAFO-810 adapter, in which case you will want to check out the instruction manual for the drivers in Adobe PDF format, that can be downloaded here. The drivers for various Windows platforms through Vista are zipped up and available for downloading here. The drivers for all versions of Windows including Windows 7 are available for downloading here.

However, you may have received the Y-105 adapter, which comes with a mini-CD. The place to look on this CD is in the USB232 directory, where you will find the HidComInst.exe installation program. This will provide drivers for various versions of Windows up to and including Windows 7. If you lost your CD, you can download a zip file of the installation files here.

The pskmeter.exe application displays "PSKMETER NOT RESPONDING" only when the transmitter is keyed up. How do I fix that?
This is symptomatic of an antenna with a very poor SWR. In such cases the percentage of RF that is reflected back to the transmitter is high, and this stray RF is quite sufficient to disrupt the communication of the meter with the computer. The main clue to this is when the software reports "PSKMETER NOT REPSONDING" only during transmit. Here are some things you can do:

1. Connect a 50 ohm dummy load to your transmitter in place of your antenna. You should stop seeing "PSKMETER NOT RESPONDING". This demonstrates that the problem is with stray RF, and not with communication problems between PSKMeter and the computer.

2. When your transmitter is connected to your antenna, but NOT connected to pskmeter, you might continue to see PSKMETER NOT RESPONDING when you key up the transmitter. The reflected RF is coming through the ground connections in that case.

3. The best solution is to put an SWR meter on your antenna and trace the problem there. There is either some poor coax, or coaxial connector, or some broken part to your antenna proper. If you can achieve a good SWR the problem should be resolved.

4. Short of getting a good SWR at the antenna and feedline, the next best thing is to put a tuner between the feedline and the pskmeter and tune for a good SWR.

5. Another practice that is helpful is to put ferrite beads on all the leads in your psk31 setup: beads on the audio cables, beads on the power to the pskmeter, beads on the serial cables, etc. I have even put beads on my keyboard and mouse cables. All of this is for the purpose of choking RF that appears on ground wires.

The pskmeter.exe application displays "PSKMETER NOT REPSONDING" only when the transmitter is keyed up. How do I fix that?

This is symptomatic of an antenna with a very poor SWR. In such cases the percentage of RF that is reflected back to the transmitter is high, and this stray RF is quite sufficient to disrupt the communication of the meter with the computer. The main clue to this is when the software reports "PSKMETER NOT REPSONDING" only during transmit. Here are some things you can do:

I hear a beeping noise from my radio. What should I check?

I built the PSK meter and it seems to be working. However, there seems to be a beeping noise coming from the PSK meter from 2.5 MHZ to about 17 MHz that is heard in the radio. If I change the sampling rate, the beep will match that. I have powered the PSK meter with just a standalone 9 volt battery and I still get the noise.

This can be a symptom of a poor connector or cable connected to the PSKmeter. For example, check the BNC connector that it is making good contact to the coax.

My computer doesn't have COM1 or COM2, so PSKMETER will not start. I want to use COM6. What do I have to do?

The solution is quite simple. Using Windows notepad, open the file pskmeter.ini located in your C:\WINDOWS directory (if you are using Vista or Windows 7 see the note below). There you will find the following specification:

Edit the port number to the comport you plan to use. For example, if you would like to use ComPort 6, edit the Port= line to read Port=6. Then save the file and close notepad. When you start the PSKMeter application, it will open and use the com port you specified.

If you are running Vista or Windows 7, the pskmeter.ini file will not be in the C:\WINDOWS directory. Instead look for it in either:

c:\Desktop\<your name>\AppData\Local\virtualstore\windows
c:\users\<your name>\AppData\Local\virtualstore\windows
where you should replace <your name> with the user name you are logged in as.

Whenever I select 'Show Power' I have to select QRP or QRO regardless of how the jumper is set on the board. Having made a selection (say QRO) it works but if I exit and restart the program, the setting I chose before has not been saved. I have to both select, 'Show Power' and 'QRP/QRO' again. This is necessary everytime I run the program. Is there a way of permanently fixing this setting in a configuration file or with command line parameters?

This problem has been fixed starting in version of pskmeter. You can download a copy of the latest version by clicking here:pskmeter.exe.

I have a Vista computer and want to use the USB to Serial converter. Where can I get the driver for Vista?

If you have a BAFO-810 USB to Serial converter, you can get the driver for Vista here. If you have a Y-105 USB to Serial converter,  you can use the drivers here.

I use Vista, but Vista doesn't come with HyperTerm. In your manual you suggest using HyperTerm as a tool to test PSKMeter. What should Vista people use?

We provide a terminal emulator program called ssiterm.exe that can be used with PSKMeter or any serial device. Download ssiterm.

Will PSKMeter work with SignalLink?

SignalLink is a computer-to-radio communication device with a built-in sound card. PSKMeter will work perfectly with SignalLink, as long as you configure PSKMeter to connect to its sound card. This is done in PSKMeter by right-clicking on the data area and selecting "Set Sound Card". You can then pick the SignalLink. After that PSKMeter will be able to control the sound card exactly the same way it would for a sound card that is installed in your computer.

The drivers shipped with the USB-to-Serial converter don't work with Windows 7. Now what?"

The drivers shipped on the mini-CD with the BAFO-810 USB-to-Serial converter currently support all modern versions of Windows up to Windows 7. If you are using a Windows 7 machine, and the BAFO-810 converter, you will need to download and install the latest drivers. Click here to download the driver for Windows 7 for the BAFO-810. If you are using the Y-105 converter, get the drivers for it here.

"How come the USB to serial converter doesn't attach directly to the PSKMeter DB9?"

The female DB9 connector on the PSKMeter is designed to mate with the male end of a standard serial cable (the other end of which would normally mate with the serial port on a computer). However, the USB to serial adapter's DB9 male connector is designed to also mate with a serial cable, rather than a device directly. The result is that to connect the USB adapter to the PSKMeter, you have several options. The first is to connect the adapter to the PSKMeter with a short length of RS232 cable. This is what most people do. However, there is no reason that the female threaded posts that are embedded in the adapter cannot be drilled out, leaving a straight hole. 4-40 screws can then be used to attach the adapter to the PSKMeter's DB9 jack. Several of our customers have done that and report that is relatively easy and works well.

"My PSK station uses a Tigertronics Signalink USB interface and the RX and TX audio levels are controlled from the front panel of this unit, how would the PSK meter interface with this unit? "

Yes, PSKMeter works with SignaLink, because SignaLink is connected to your computer by a USB interface and installs its own sound card driver. When you configurethe PSKMeter software, you just selected the SignaLink driver from the list of audio drivers on your computer, and you're all set to go.

What are the latest and greatest new features?

PSKMeter now supports PSK63. Also, both master and wave audio levels controlled for improved fine tuning. User is now able to select from multiple sound cards, and is able to set a maximum power level. Also some problems connecting to the meter under XP have been solved. Starting in version, pskmeter.exe supports COM ports 10 and higher.

How can I contact you if I have a question and I can't find the answer here?

You can contact us for any reason at Please put "PSKMETER" somewhere in the subject line.