Tag Archives: PSK

VOA Radiogram — More Digital PSK Mode Trials

Again I received fairly late notice that this weekend Voice of America is trial broadcasting several PSK mode broadcasts.

VoA Radiogram

VOA Radiogram — “Soft launch” of VOA Radiogram this weekend.

  • Modes menu for VOA Radiogram, March 23/24, 2013

    VOA Radiogram for March 23/24 will be similar to the past weekend’s program in that it features the PSK modes. Much of Kim’s script will be the same. In this weekend’s broadcast, however, only one mode at a time will be transmitted. This should improve the signal-to-noise ratio and ability to decode each mode.

    Each will be centered on 1500 Hz:

    1. BPSK31 (1:00)
    2. PSK63F (1:00)
    3. BPSK63 (1:00)
    4. PSKR125 (1:00)
    5. PSKR250 (1:00)
    6. PSKR500 (1:00)
    7. PSKR1000 (1:00)
    8. PSKR125 (3:45) Plain text
    9. PSKR250 (2:40) Flmsg* formatted (with html)
    10. MFSK32 (0:55) Image

    *Install Flmsg. Then, in Fldigi: Configure > Misc >  NBEMS > under Reception of flmsg files click Open with flmsg and Open in browser, and below that state where your Flmsg file is located.

    If decoding performance is still not satisfactory, VOA Radiogram in future weekends will feature more robust modes, such as MFSK, MT63, and Olivia.

    See VOA Radiogram: how to decode the modes.

    VOA Radiogram transmission schedule
    (all days and times UTC)
    Sat 1600-1630 17860 kHz
    Sun 0230-0300 5745 kHz
    Sun 1300-1330 6095 kHz
    Sun 1930-2000 15670 kHz
    All via the Edward R. Murrow transmitting station in North Carolina.

    Please send reception reports, audio samples, screenshots, etc.,  to radiogram@voanews.com

http://voaradiogram.net/post/45415629990/voa-radiogram-how-to-decode-the-modes

This is a neat extension of both the use of the PSK digital modes more popular in Amateur Radio and VoA broadcast mission.

73

Steve
K9ZW

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VOA Radiogram — Digital PSK Mode Trials

I received fairly late notice that this weekend Voice of America is trial broadcasting several PSK mode broadcasts.

VoA Radiogram

This is a neat adventure, as the technology could allow some significant upgrades to the VoA system.

List is:

VOA Radiogram — “Soft launch” of VOA Radiogram this weekend.

Transmission schedule (all days and times are UTC) from the Transmitting Station in North Carolina.:

Saturday 1600-1630 17860 kHz
Sunday 0230-0300 5745 kHz (Saturday evening in North America)
Sunday 1300-1330 6095 kHz
Sunday 1930-2000 15670 kHz

Instructions on using PSK to decode the modes is at:

http://voaradiogram.net/post/45415629990/voa-radiogram-how-to-decode-the-modes

This is a neat extension of both the use of the PSK digital modes more popular in Amateur Radio and VoA broadcast mission.

73

 

Steve
K9ZW

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Something to tuck away for rainy day: Popeye’s Guide to PSK the natural way

From the good folk at Radio Free Redoubt, this PDF explains how to listen to PSK – a very interesting, and in case of emergency potentially very important, amateur radio digital mode – with a receiver with some earbuds, a computer with fldigi and a piece of tape.

The PDF is “Popeye’s” article with the comments distilled into an paragraph appendix.

Of course other PSK software will work. The fldigi selection is solid and it is available for a lot of platforms.

This works – at our club we’ve done a demo doing it this way, including adding the other link between the computer & in our case transceiver to do the transmit side.

The technique fits very well with the Freecom idea of personal preparedness.

Source URL for fldigi http://www.w1hkj.com/

Download URL for fldigi (Linux, Windows, OS X, Puppy Linux and Source) http://www.w1hkj.com/download.html

Original Post at Radio Free Redoubt http://radiofreeredoubt.blogspot.com/2012/03/how-to-receive-ham-radio-digital.html

The Radio Free Redoubt main page http://radiofreeredoubt.blogspot.com/ (expected to change this Spring to http://www.radiofreeredoubt.com/ – that URL is presently in testing and will make their website MUCH more readable!)

Tuck this away for rainy day. It is worth downloading the fldigi program mentioned, as a “just in case.”

Of course you can try this now too!

73

Steve

K9ZW

LINK to the PDF: Popeye’s Guide to PSK the natural way.pdf

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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:

KK7UQ IMD Meter

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.

73

Steve

K9ZW

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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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
www.nue-psk.com

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


73

Steve
K9ZW

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