Tag Archives: PSK31

For Want of Nail, Nothing Like an Upgrade to Peak Interest, and Playing with Go-Kit Gear

In the run up to Dayton my Shack Computer had been acting up. Latency Spikes and gremlins that were giving PowerSDR no end of grief. Thought a decent dual-core Dell, I was even considering replacing the machine.

Troubleshooting found only erratic symptoms. The underlying cause(s) just weren’t easily found.

On return from Dayton middle son Winston KC9FVR/AG asked if we could run up the station so he could try some PSK31, having been reading the Digital HF book bought at the ARRL booth. We couldn’t get things to run very smoothly and after a very rapid shutdown in response to a sudden lightening storm powerful enough to set fire to buildings only 10 blocks away, the system would no longer recognize the Flex-5000A hardware.

Utilities and Testing showed that the OEM Dell Firewire card gave up the ghost.

Quick research at the Flex-Radio Knowledge Center & Forum Archives identified the best cards for performance and roughly $25 later a card was on its way rushing from Amazon.

Took the downtime to do ALL updates – from BIOS to any driver/software/system update that could be done. Also left the machine running a very in-depth anti-virus scan which ran overnight (all clean enough to pass).

The new card was truly PnP (Plug-n-Play) and despite having a different chipset than advertised (putting it into an OK-class rather than preferred-class for PowerSDR use) the system quickly reinstalled the “Found New Hardware” of the Flex-5000A.

Operator error led me to fight with VAC (Virtual Audio Cables) and settings – trouble I could have avoided by a simple reboot.

Once running it was lickety-split to help Winston KC9FVR/AG put a handful of PSK31 QSOs under his belt.

The drive that comes from a fresh license upgrade and an experimenter’s mindset had Winston KC9FVR/AG quickly asking – can I run fldigi from my Linux Thinkpad using some of your other gear?

So to the garage to raid the go-kit stash.

Up went the 20m Hamstick Dipole on 12 feet of surplus cameo-poles and a trial of a Small Wonder Labs PSK-20 I had ended up with somewhere along the way.

We had little joy with this setup, and it is uncertain if the PSK-20 is needing repairs or if we were struggling with Linux sound issues.

So out came the SGC-2020 Transceiver and the NUE-PSK Modem. This combination hadn’t really been used. The NUE-PSK modem had come back a few weeks ago from a full update at Midnight Solutions bringing it up to Version 5 with all the add-on features, and the transceiver had been run but once.

Plugged in the SGC-2020 and cabled up the NUE-PSK and “PING” we were on the air just that quick.

Winston KC9FVR/AG complete a QSO and then declared the micro-keyboard “worse than texting” and dug out an old full sized IBM clicky-clicky keyboard which worked wonderful.

Of course we weren’t about to read the manuals any further than the absolute basics to get things running, so we were hand-typing everything. Macros are for sissies (or for those who read the manuals).

Winston KC9FVR/AG downloaded a PSK31 app for his Android Phone and it was neat to see it decode from the speaker’s sound output.

I ran a handful of QSOs (it is sure a lot easier to type “K9ZW” than what it took him to type “KC9FVR/AG”) before we put the station away (took ten minutes to pick up everything and store it again.)

My go-kit HF gear did digital just fine! Power needs are such that I think I could get more than 12-18 hours of full duty out of each of the gell-cells I have set aside from their storage charge levels, and days if they were topped off first.

Remember that “spark of interest” that comes with a fresh license upgrade? Well it was back down to the shack to run a couple 20m & 160m JT65 demo contacts before promising each other that we would run some Hellschreiber on the weekend.

A couple things learned – in terms of the station the dead firewire card really put the main station out of commission. “For want of a Nail” they say the battle was lost, and for want of a working firewire port the station was off the air. Critical Key Component Dependency is not unique to an SDR setup, as most stations lack backups for mission critical items. Almost nobody has a spare for each item in their station.

Then the joy of seeing an inquisitive mind wanting to explore amateur radio shouldn’t be missing from an operator’s life. It was wonderful to help Winston KC9FVR/AG explore digital-HF and heartwarming that he would only let this father retire for the evening by making a promise for “more radios, more!” on the weekend!

And lastly that it is great fun to pull out the go-kit gear and give it a whirl. Couldn’t think of a finer father-son activity to put one’s work day aside.



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Thinking Mobile, on a Simple Basis

Just back from my first trip of 2011, with at least six more trips planned or in the final planning, and about six more expected beyond the initial count. Most will be like this one, mainly work with a bit of personal time tagged on to the trip.

This last trip didn’t lend itself to traveling with radios, especially as I would have little opportunity to set-up and work a station, and that we traveled as a group of seven with events scheduled throughout.

Several of the next trips will be easier to travel with radios, and should have some “solo down time” where I could operate.

Thinking of traveling with two separate set-ups besides a full portable HF SSB/Digital setup for long stationary vacation time:

  1. The Satellite Set-Up where I will be in any one place for less than two days and/or will have at most limited operating time. In addition to the laptop I typically already have to take traveling for work, the gear would easily fit into a briefcase, would take less than 15 minutes to set up, and could be a real challenge with rewards for any QSOs I could score.
  2. And second a PSK-31/Digital Set-Up for trips where I’ll be somewhere more than an overnight or two, will have a likely spot to put up a basic antenna, and operate for at least a few couple-hour sessions. Figure that I can fit everything into half a suitcase and under 25 pounds with some care. NUE-PSK Modem, a small 20 watt or less transceiver & matching power supply, and an ultralight antenna should do the trick.

For drive-to trips it might be just as easy to take my portable HF station, rather than fuss with a small station.

Very undecided about whether to take any gear out of country – whether it is going to be worth the effort given the nature of those trips. Maybe next set of overseas trips will have a better Amateur Radio profile.



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REPOST: Meter Meter on the Wall, Who has the Fairest PSK Signal of Them All? The Clint Hurd KK7UQ PSK Meter Kit

LINK Updates June 2012
Meter Sales page is now: http://www.Navigator-Interface.com/naviusa_010.htm
eHam reviews of the meter: http://www.eham.net/reviews/detail/4210


REPOST & UPDATE:  Had a very nice QSO with Clint KK7UQ by PSK31 using the Flex-5000A and after discussion decided to repost an update on his excellent PSK31 IMD Meter.  I originally built a kit version, but presently only a fully built version is offered.

This has to be one the most fun kits to build where the finished product is something you just can’t buy easily – the KK7UQ IMD PSK meter.

Clint KK7UQ is a wonderful person to deal with, and I’ve had the pleasure to work him as well. His meter concept is simple:


The RF signal is picked up by a short whip antenna on the meter, fed into an AGC controlled RF amplifier, the signal is detected, sampled with an A/D converter under the control of a micro controller. The signal is analyzed by firmware on the micro controller and the equivalent IMD is calculated and displayed on a 3 digit LED array built into the IMD Meter. (from Clint KK7UQ’s website)

Since not all of us are up on the jargon, let’s run it down.

PSK – Phase Shift Keying – One of the Most Popular Digital Modes (usually PSK31 or PSK63 – the numbers indicate speed) – Full write up at: http://en.wikipedia.org/wiki/Phase-shift_keying

IMD – Intermodulation distortion – The “noise” sub-optimally tuned up PSK transmissions are prone to. – Again a fuller nice write up is at the Wiki: http://en.wikipedia.org/wiki/Intermodulation_distortion

A/D – Analog to Digital converter – basically this circuit digitizes for processing an analogue signal – see: http://en.wikipedia.org/wiki/A/D

AGC controlled RF amp – A radio Frequency Amplifier with Automatic Gain Control

The IMD Meter Building Experience is one of great fun and an outstanding product when you’ve finished.

The Kit version had been available directly from Clint KK7UQ or the recently added Fully Assembled version from RigExpert [edited 02 DEC 2008]

UPDATE  From Clint Hurd KK7UQ – 02 DEC 2008:

Hi Steve – I enjoyed our QSO yesterday on 20m PSK. You asked for comments on the IMD Meter page. I have 2 comments: 1) The reference to “RigExpert” with accompanying URL is no longer valid. It should be changed to: “USInterface” with the URL of http://www.USInterface.com SEE ABOVE June 2012 Updates 2) The IMD Meter is only available in fully assembled form from US Interface. I no longer provide kits. Thanks for the nice writeup. Clint KK7UQ

Steve – some additional thoughts:

When the IMD meter was designed, the FS (field strength) was added as an afterthought. The number output is related to the attenuation of the AGC circuit – it turns out to be about 1 dB per digit. I have found, and others have told me that the FS is useful. In my case, my antenna is an 80 meter full wave horizontal loop, located several hundred feet from the shack. I have a remote tuner there to minize transmission line loss when the frequency is away from the resonant points. I use the FS mode to let me know if the tuner is working and that RF is actually getting out. Of course, the FS varies from band to band, since the pattern of the antenna changes with different bands, but the FS per band is very repeatable. I have already detected a bad connection at the feed point, and a tuner that didn’t like running in contest mode for 6 hours straight.

Another case was a Russian ham who used his IMD Meter in FS mode to help tune his mobile screwdriver antenna.

So this has turned out to be more useful than first thought.

The IMD Meter is manufactured in the US. N3JJA manufactures the IMD meter; sales and service is by Glenn W3GWW. The parts, of course come from all over the world, but the PCB, the cases and the assembly are all done in this country.

Glenn W3GWW also sells the Navigator interface which is one of my designs. It is also manufactured in the US. Assembly is done by automatic equipment in California, testing is done in Washington, and sales and service are done in Maryland. The unit has undergon Part 15 FCC certification and is designed and manufactured to ROHS standards.

73, Clint KK7UQ

Also a nice checklist for a PSK station setup can be found at:http://www.psb-info.net/Station-Setup-Checklist.html

Either KK7UQ’s IMD Meter has my Recommendation, and are a welcome addition to any shack with digital operations.




Original Post: Meter Meter on the Wall, Who has the Fairest PSK Signal of Them All? The Clint Hurd KK7UQ PSK Meter Kit

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Flex-5000A on Digital – First PSK on the New Flex-Radio at K9ZW

Took a few minutes (would be quicker if I read the directions) to set up the Flex-5000A to use MixW and a neat internal interface called “VAC” (Virtual Audio cables) to set up the Flex-5000A for Digital Mode.

Here is a screen shot:


First Flex Digital at K9ZW

First Flex Digital at K9ZW

I’ve a ways to go to make this all work as I would like it to.

BTW with the speed of the new machine it looks like all my logs could be merged.  I had avoided this on the old XP Box as it was easily overwhelmed whenever my logfile got big.

For details on the setup using MixW and VAC see the Knowledge Base and Manuals at Flex-Radio.



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NUE-PSK Modem Gains USB Logging Ability

This just came over the reflector:

USB card for NUE-PSK modem … nearly ready!
Posted by: “George Heron N2APB” 
Mon Sep 1, 2008 12:08 pm (PDT)
Hi all,

Here’s an update on the progress with the USB add-on project for the NUE-PSK Digital Modem … full details and photos, schematic, etc are on the modem website at www.nue-psk.com/usb.

The “NUE-USB” add-on card development is nearly complete and we are awaiting production cards from the fab house. We’ll start taking orders shortly and we can start shipping in about two weeks when the pc boards are received!

In a nutshell, the USB add-on card will make your NUE-PSK Digital Modem more flexible and more useful with its ability to record QSO receive and transmit text to a USB flash memory stick for archival and remote printing. The USB card also provides a serial connection to a PC, a port for a USB printer, and (soon) a real-time clock/calendar function to timestamp QSOs. The updated modem software contains the new keyboard commands for controlling the USB card functions, plus a wonderfully-revamped and consistent text editing commands.

The USB card fits into the existing modem enclosure with minimal modifications. The card occupies the battery compartment, since most users let us know that they would gladly sacrifice the use of internal batteries for this USB capability. (Battery operation of the modem is cool also a cool feature and it can indeed run up to 8 hours on a pair of 9V batteries, but we found that most people use the modem with an external source that also powers the transceiver.)

The USB card will be available for purchase in a variety of ways …

1) Fully assembled & tested — Make a few easy mods to your modem, load up the latest modem software, plug in the USB card and start recording QSOs!

2) Partial kit — PCB and all parts are supplied, with the LQFP 48-pin surface mount controller attached and programmed. You just attach the remaining parts.

3) Full Kit — PCB and all parts are supplied. You attach the LQFP 48-pin surface mount controller and program it yourself with a PC serial port and free software.

4) Modified Enclosure (optional) — Lower half of the aluminum enclosure clamshell with mounting and connector/LED access holes.

5) Full Factory Upgrade — Don’t want to do any of this yourself? Just send us your modem and we’ll return it with the USB card fully installed and operational.

Prices are not yet established, but we’ll be keeping them as low as possible to make it easy for modem owners to upgrade. We’ll be announcing prices next week (Sept 8th) and will start accepting orders then. Meanwhile check out other details below …

USB Card Features …
1) Recording Rx and Tx text from the LCD to a USB flash drive (memory stick) — The main intent of the “recording” feature is to capture the Tx and Rx text streams for later archiving and/or printing from one’s PC. The “recording” function we are putting into the software and the file that we are saving to the USB stick captures whatever is coming across the LCD. Whatever you type during Tx mode, and whatever you see in Rx mode is exactly what gets saved away during our “logging” process. (This is in contrast to any kind of a formatted, standards-based, time stamped line of data containing callsigns, signal reports, etc. We will not be doing this type of extensive formatting in the modem – it is just too much effort and there is not enough code space to deal with this.)
2) USB Flash Drive Boot Loading — With the ability to read data from the USB memory stick comes the feature of boot loading new modem software loads directly from the stick, instead of needing to be tethered to the PC serial port for programming new versions of modem software. In fact, one can have multiple software versions on the USB stick, each containing support for different modes of operation (PSK31, RTTY, CW, et al) … just plug in the thumb drive and load in the desired mode you wish to operate! This will be convenient, as in the near-term we intend to provide separate software versions for the different modes of operation. (The current software architecture and memory availability in the dsPIC memory prohibits co-resident modem algorithms.)

3) Built-in USB connection to the PC for “field programming” of modem software updates — Once the modem is updated with the latest software (containing the USB feature support), the USB card’s “B” connector will allow a USB Host cable connection to the PC for download and programming of new software releases, as well as for communication with other devices.

4) Built-in USB printer port — Provides for realtime printing of the Tx & Rx data streams (the same, raw Rx and Tx QSO data, as seen on the LCD.) [Software support not yet available … popular printer protocols will come in later software releases after initial deployment of the USB card.]

5) Built-in Real-Time Clock/Calendar (pcb traces only) — Provisions have been made on the board to support a PIC controller in order to maintain current date and time, ultimately for use by the modem and in the recorded data going to the USB memory stick. Other than the schematic and board layout supporting the PIC circuitry, this feature has not yet been designed – it is hoped that others will help out by adding to the Open Software modem project. The task involves designing the PIC software and hooks in the modem’s dsPIC software … a separate Modem RTCC requirements document is available for those wishing to help with the project.

Design Notes …
The USB board plugs into the main board by means of a mating female connector to the modem’s P4 “Field Programming” pinheader. Minor and easy mods are required on the modem pcb to supply 5 volts to the P4 connector (instead of 3.3V), and to bring two extra control lines out to a new connector that plugs into the USB card. The USB card is the same y-dimension as the modem board, and it extends 1-1/8″ in the x-direction over to the left edge of the enclosure. The board sits even with the main board, supported by two standoffs on the left side and a 4-position SIP female header on the bottom that extends out the right side of the board to plug into the existing P4 connector.

The heart of the design is the Vinculum VNC1L FTDI controller chip. Although more expensive than “USB bit banging” alternatives, the VNC1L chip provides support for the full USB protocol control, and a DOS-like command line interpreter that allows easy writing and reading of a flash disk, making it a relatively easy design-in for USART ports such as we have available on the NUE-PSK modem. (For a great overview of the product, see the July 2007 issue 204 of Circuit Cellar magazine http://www.circuitcellar.com). Additionally, the VNC1L chip offers Host mode support, which allows the USB card to serve as the “serial interface” to a PC, providing a way to load modem software into the dsPIC as before, as well as providing communications to other devices downstream.

A real-time clock/calendar (RTCC) function is optionally possible on the USB card in order to keep track of date and time, even with the power removed from the modem. The concept is that the PIC monitors the modem’s UART port for an “RTCC data request”, whereupon the PIC switches data path to send the date and time information to the dsPIC. The new/replacement bottom half of the enclosure will continue to have the battery cover plate present to allow accessing the coin-sized battery that powers the RTC circuit. (NOTE: Although the RTCC circuit traces indicated in the schematic are indeed provided on the traces of the pc board, the RTCC functions and components are not provided in the initial NUE-USB cards being sold. We did not have time to complete this lesser-important product capability, so we put the framework in place with hopes that some one else can step up to help with this Open Source design.)

73, George N2APB & Milt W8NUE

I’ll be upgrading mine as soon as the full release is out!



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Dayton Hamvention 2008 Follow-Up Report No. 3 – NUE-PSK Team

Milt at AmQRP\'s NUE-PSK Booth at Dayton 2008


I had a long chat with Milt Cram, W8NUE at AmQRP’s NUE-PSK Booth. Though I received the NEU-PSK modem I ordered under the early-bird program a few weeks before Dayton, I had made less than 20 QSOs with the unit and was eager to learn more.

Presently there is a firmware update that Milt W8NUE offered to install if I had my unit with me. (I didn’t)   Future Firmware Updates are planned to expand the ability of the modem! 

Additional Modes and Logging Ability are high on the list.  Following the NUE-PSK reflector since Dayton some of these features are becoming reality, and again I need to get out the same interface I use with my Arduino boards to update firmware.

Fellow AmQRP team members were final assembling full kits for sale at the booth and demonstrating the modem to the gathered crowds of amateurs.

Not surprising that this excellent Modem Project has a personable and excellent team behind it!

Here are some of my previous articles on the NUE-PSK Modem:

AmQRP Releases a Significant Upgrade to the NUE-PSK Modem 

First QSO’s with NUE-PSK Digital Modem 

NUE-PSK Unit Arrives at K9ZW 

NUE-PSK – Huge Amateur Support for AmQRP PSK Project 


AmQRP’s “NUE-PSK Digital Modem” Reviewed in QST and QEX 

Field Portable PSK without a Computer – AmQRP’s NUE-PSK Digital Modem 



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