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January 5,  2003

You might have heard me teasing about something new coming to the SFFMA. It's finally ready.


You can now hear the 147.000 Repeater almost live. I call it the "147.000 Archive." I have set up a system that automatically records the 147.000, saves the audio as .mp3 files, then moves them to the web site. This is done about every 5 minutes, so you can usually hear what was said in under 10 minutes. The audio for the last 3 days will be available. This means you can hear how that conversation you were in ended. No more sitting in the driveway waiting to hear how things turned out. You can also hear what the topic was during yesterday's drive time. You can also hear for yourself how your rig sounds on the air.  Here's where to go:

To get the most out of this system, you'll need to look carefully at the file name. For example:

20030105133950.mp3 is set up as Year, Month, Date, Hour, Min, Sec, .mp3

So this one was recorded January 5, 2003, at 13:39:50. The files are displayed with the newest at the top.  In case you're wondering, the time stamp is for the moment the recording started.

Click on the file and it should load and play on your speakers. mp3 is a popular format for audio over the net, so there's a good chance you'll have a player configured on your computer.  I suggest Windows Media Player, version 7.1 which is available here for free.

You'll see lots of small files, less than 20k. Those you can ignore, they're usually just a single key-up. The bigger the file, the longer the series of transmissions.

You might wonder why you don't hear the ID's and courtesy tones. The way our Trustee, John, KU4GY set up the repeater made this easy. The repeater only puts out a 94.8 PL when the receiver is actively receiving a signal. No signal, like after you un-key, no PL. No PL and I'm not recording. The software does use a vox circuit, so you might lose a syllable at the start of some files.   This is already on the list of things to improve later.

I also hope we can use this system to improve our operations at events. I'll save the files from big events so we can review them together. When we hear ourselves we'll hear things we didn't realize we were doing on the air. Embarrassing at first sometimes, but it's the best way to get better at what we're trained to do.  You can also use it to hear your microphone technique. Find out if you're eating the mic, or too far away.

If you want to save a file, right click on it, then select "Save Target As" and you'll be able to save the file to your hard drive.

Thanks to Brendan, KG4DKF for helping with the final set up.

Please try this system and let me know what you think.   ray (at symbol) rayvaughan (dot) com

Ideas to improve the system

bulletCome up with a utility that can delete files based on file size.  I'll run this once an hour to get rid of those <20k files that are just repeater key-ups.   
bulletBeg a Java programmer to make an application that will allow a web site visitor to select a file by date and time, then play the following files, in order, automatically until the user stops the process.   UPDATE:  Now that I can generate a play list (.m3u) compatible with Windows Media Player, this works almost as well.  
bulletChange from software VOX operation to PL decode.   This should minimize the first word being lost.   A time delay on the audio line will make sure the recorder is going before the first word is spoken.
bulletDevelop a program that will move the files into a zip file, based on date, to a local directory.   This would allow for a long term archive. would be make up of all files 20030105*.mp3.   This process could be done right after midnight each night.   I need a utility that can do this.  I think there might be some log archiving programs that could be adapted for this.   
bulletTime Sync the server so the file names will be very accurate. Done
bulletLook for freeware to do the same function as the the registered shareware software I'm using now.  In the true spirit of ham radio, I like to do things as cheaply as possible.   The good news is that even with the shareware, it's less than $150 for software.  This is where a amateur/programmer could really help.

If you can direct me to any utilities that can do any of this, please let me know.   If you're a programmer, I could use your help.   Thanks.


In case your interested in the legal aspects of doing this, here are some interesting links.  Thanks to Wendy, KG4OXT, for looking these up:

Florida Law  Look at 934.03 (2) (h) 1 and (h) 2 c.

Federal Law  Look at the third paragraph

And here's the FCC's Amateur Radio Expert's opinion:

-----Original Message-----
From: Riley Hollingsworth [] 
Sent: Tuesday, January 07, 2003 8:37 AM
Subject: Re: Recording Repeater audio
No--Amateyr communications can be recorded freely, and we do not
regulate the web.
>>> Demos Doulou 01/07/03 05:44AM >>>
Hello sir, 
What are the legalities of a individual recording conversations from a
ham repeater and making those recordings available on a Internet web
Do the users of that repeater need to be notified that they are being
Thank You 
Demos Doulou 


If you're interested in doing this for your club repeater, check back in a few weeks.  I hope to have a complete 'how-to' guide soon.   Here's the problem: One of the key elements is software I'm beta testing for the author.   I don't want to mention it until he has created a release version of the software that includes what you'll need.  He doesn't need a load of people bugging him right now.  He has been extremely responsive to my suggestions  so far, I don't want to ruin that.  At this point I can suggest that you save about $100 to get ready for it.   

I can tell you a few things about the setup.   This system is not connected to the repeater directly.  It picks up the audio like any other radio.  The radio is a Motorola Spectra... for now.   I do hope to upgrade this to a GE Mastr II voting receiver.   That will allow me to use PL to trigger the recording, not just VOX.  That should help prevent lost first words.  If I add a second or two of audio delay, I might be able to get every bit of the transmission. The only down side to the GE Mastr II is that I'll need to buy a crystal.   But I really like the receivers, so it's worth the $25 or so.  If you want to avoid the recordings having CWID and beeps, set up your repeater to send PL only when the receiver is active.   See the description of how this works above.   

The computer is a used Pentium II, 350 MHz.   Not a screamer by today's standards, but fine for this.   Look for those old computers at work that no one wants any more.   Load up a clean install of Windows 2000.   I suggest at least a 4 Gig drive (common in the 350 MHz days) or larger if you're going to keep the logs locally.   A full time, high speed connection to the Internet and your remote web server is needed.   Dialup might work, but you could end up having more .mp3 to transfer than you have time for.   WS_FTP does have an option to do dialup... but I haven't used this function.  You're on your own there.

[Mystery stuff happens here, sorry, keep checking back]

The directory that has the .mp3 files is checked every 5 minutes using Win2000's Scheduled Task manager.   The software is WS_FTP Pro.   I can highly recommend this software.   Well worth the $40.   You can buy it on line.  Set up the Synchronization Utility to keep your local directory and one on the web server (the bottom half of the web page) the same.   If it's on the local machine but not on the web, copy it over to the web server.   If it has been deleted locally, delete it on the web server.  Be sure to exclude .wav files from the transfer (that will make sense later).  Every 5 minutes you'll see the Sync Utility pop up, log in, do a quick inventory, then transfer and delete as needed, then shut down.   

You'll need a web server that allows its content to be viewed by visitors.    I'm not sure, but this may rule out Windows based servers.    

Use FrontPage 2000, or your favorite web authoring software to generate a frame page.   The top explains the naming convention and the bottom is the directory where FTP put the files.   

As you can see from my wish list (above) there's even more that can be done.   It is my hope some ham radio software developers will step forward and make some programs that will do this and then move this concept into new services, applications and ideas.    

Play List (added 1/10/2003)

I got many requests for a way to listen to all the files without clicking on each one.   Problem solved.   The key to this is a play list.  Programs like Windows Media Player ver 7.1 look for catalog files ending in .m3u.  When you give it one, it looks for all the files listed in the catalog.   Then it picks the first one, plays it, and when that is over, it plays the next one and so on until it reaches the last file.

Lucky for us, the playlist is very easy to make.    It's just a listing of the directory, files only.   Again, the Windows scheduler comes to the rescue.  It runs a simple batch file every 10 minutes.   Here's one of the two:

echo Making current playlist, playlist1.m3u
del playlist2.m3u
echo playlist2 deleted
dir /b *.mp3 > playlist1.m3u
echo Done making playlist1

The key is the line: dir /b *.mp3 > playlist1.m3u  That > sends the directory to the file instead of the screen.   The /b means to omit the usual stuff you get before and after the file names.   

One little catch... In my case, the server is in GMT, the encoder is in EST.   So when the ftp program goes to upload, it thinks the one on the server is 5 hours newer than the one it has locally.  So the remote one is not replaced.   The trick I used to get around this is to have two different file toggle.   One created one minute before an upload.   It gets uploaded along with the .mp3 files.   Then, 5 minutes later the other batch file runs, deletes the first, then makes the other play list name.  At the next sync, the old one is deleted and the new one is moved.   This goes back and forth every 5 minutes.   So at any given time, one of the two will be on the site and current.   If you can think of a way to use the same file name, please let me know.

When you use this play list approach, it's very easy to sit back and listen to a day's worth of conversations in just a few hours.   You can scroll up and down the list to find times that you want to listen.   If you're not a morning person, you can listen to morning drive over dinner.    It's much easier than clicking on each individual file. 


At 14:50 on 1/7/2003, I changed the mp3 data rate from 16 to 8 kbps.   This was done to reduce the storage space required on the server.   Since Saturday, we have used 100 Megs of storage.   I had hoped to keep 5 days of audio on the server, but at 16 kbps, we would only be able to have two days.   Let's see how the audio quality is at this much lower data rate.  An added bonus: the files will take half as long to download to your computer.

Also, today I noticed the volume on the radio had been turned up to high.  Some of the recordings from today may sound distorted.   If we move to a dedicated receiver, this won't happen again.  

1/7/03 16:30

Okay, bad idea, I admit it.  8kbps sounds a bit weird on good sounding mobiles, but if they're over-deviated, they sound terrible, almost like someone is whistling in the background.  I set it back to 16kbps.   Too bad there's nothing in between 8 and 16kbps.   We may need to find more space somewhere.


Worked with Brendan, KG4DKF, on the monthly archive.   Files from the first of the month are now available on-line.  This should automatically reset on the first of the month.   Many of the days in November were lost.  Sorry.   The monthly directory was too full and the system was running slow and then crashed.   I was too busy with the FTAA in Miami to spend time on the system.   Now, hopefully, the current month directory can never get too large.  However the hard drive can still fill up, so I'll still have to pay attention to the system every few months.   The good news is that other than running out of space, the system can run about two months without human intervention.   Get me a large hard drive and it could go even longer.   However, files available on-line will be limited because it's hard to find web space on the net for free, especially when you need a Gigabyte per month.   We're very luck to get what we have now.  

Needed:  A simple DOS program that can be run from a batch file that will automatically delete files below a certain size.   That will help me clear those annoying 10 second files that are just someone checking to see if they can hit the repeater.   Something like  KILLSHORT 14000 would delete any file in the directory shorter than 14k.   If dig deep enough, I bet there's an old BBS utility that does this.  Let me know if you have (or can write) such a utility.   Thanks.


After over a year, I lost the free server space I had been using for today's files.  They said I had exceeded my quota.   I just pointed today's files to a brand new web server I own.   The files from this month and last month will remain where they are for now.   You might see a slight difference in how they appear.   This is a Linux box now rather than Windows.  

A final thought:

They say information is today's industry.   We have many gifted amateurs with lots of wisdom and experience.   While many repeater conversations are boring even when they were live, others include some great information and history that may never be repeated again.  While I wish everyone would write up their thoughts, it's just not practical.   Let's make an effort to get this recorded for the future.  CDRs are cheap.  We've already lost many of our most important voices.  Record and save... in a few years you'll thank me.  

03/24/2004 21:13:04 -0500

    South Florida FM Association, 2003   

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