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In many of my ham radio related posts, I make mention of PL Tones, CTCSS, and sometimes just refer to it as a tone. I have come to realize that I have never really taken the time to explain what these things are.

CTCSS stands for Continuous Tone Coded Squelch System
PL is a term that was created by Motorola and stands for Private Line
(both of the above are basically the same thing and the terms are often used interchangeably)

These tones are a sub audible tone that is injected into the signal just before it leaves the transmitter. The tone settings on radios usually have two basic settings: Tone and Tone Squelch (most of the newer radios also have a Digital Coded Squelch) for the user to choose from. I have never used or played with the Digital Coded Squelch so cannot say for sure, but it probably works similar to the Tone Squelch setting.

First, with the Tone setting turned on, the radio will add the sub audible tone that you have selected with each transmission. This is important because it is often necessary to use this setting to make use of repeaters on the VHF and UHF bands. In this setting, the receive function of the radio is not affected and the radio receives as if the tone were not turned on.

With the Tone Squelch setting, the radio will continue to add the tone when you transmit, but it will also listen for the tone when receiving. If the tone is not heard from the transmitting radio, your radio will remain muted and you will not hear whatever traffic is happening on that frequency.

As an interesting side-note, this is the system that is used by FRS radios when they advertise having “38 Privacy Codes” within each of their 15 or 22 or however many channels. The thing is, these “Privacy Codes” don’t really make it private because anyone who has them turned off and is on that channel will hear any traffic on that channel.

Ok, that explains what PL Tones are and how they work, but what’s the point and why are they used? Well, it depends on the situation, but there are 2 main reasons that they are used. The first reason would be to have multiple users on the same frequency or use the same frequency for multiple purposes.

For an example of the first part of that, think of the FRS radios that I mentioned before. While it doesn’t necessarily offer any additional privacy or security, you and your friends can be on the same channel as someone else but not have to hear what they are saying and you would still be able to hear your friends. In order for this to work, both radios (your’s and your friend’s) would need to be using a “Tone Squelch” implementation of CTCSS tones.

An example of using the same frequency for multiple purposes would be when using VoiceAlert on APRS. When using this APRS Radar, the CTCSS tones are used to determine what signals are within simplex range and the ones that are not do not have the tone on them.

The other reason for tones to be used, and the reason that is most likely in ham radio implementations, is to limit interference in high RF environments and decrease the amount of static bursts that are heard. This is especially important on repeaters where noise coming into the repeater would then be re-transmitted and heard by all users on the system. Along these same lines, many repeaters also generate a PL tone on the repeater output allowing users to use “Tone Squelch” rather than just “Tone” so that they will not hear other interference sources on the frequency that would otherwise open the squelch on the their radio.

Well, my Market Leverage bag of stuff arrived on Thursday and I was pretty excited about it. However, other than a brief look, I didn’t really play with or use any of it until yesterday. I brought the Flip along when my friends and I went to go watch fireworks. Some of them were grilling out when we got there, but the rest of us had grilled out elsewhere earlier in the day. I think I am going to like the Flip more than I originally thought I would.

Sorry about the shoddy editing, but I put this together in a hurry. I know there is no sound, rather than having you hear snippets of conversations, I decided to make it a silent movie I will try to post more on the bag of stuff and the Flip later.

This week I’m not going to be very good about using anchor text that will be beneficial to the people I’m linking to. On the other-hand, it will be fun for you because you won’t know where the link is going to take you until you click on it Have fun!

This guy took over this blog (did it get taken down?) that this guy is supposed to be posting on and keeping updated. However, he doesn’t care that he can’t post on the blog he is supposed to be.

This lady blogger came back to the blogosphere after an extremely long hiatus, we can only hope that she keeps updating. Oh, and this guy came back too!

Then there is this guy that has decided to do a permanent change of address (coming soon) and is going to implement a new theme design at the same time.

Meanwhile, this other guy made considerably less money from his internet ventures than he did last month. Don’t feel too bad for him, he still made a pretty decent amount though.

With all that is going on in the world, some people would rather do things the hard way and be a slave to the clock rather than query a database. Oh well I guess, at least I got some recognition from it. Oh, and he is giving a way a box of stuff so check that out if you’re good with Photoshop.

Last but not least, this girl was concerned about the neighborhood kids; and then they were at it again!

Previously, the Prosper referral program was set to end on June 30, 2008 and, while I had posted on the program before and do feel it is a pretty good deal for those who participate, my plan was to remove the Stripe Ad at the top of my site and take the 125×125 promoting it out of rotation.

Before removing these links promoting that post, I decided to check with the Prosper website and read the announcement declaring the end of their referral program. Imagine my surprise when I went to that site and find instead that they have determined that there will be no end date for their referral program.

Since the program is still going on and I am still broke, I am going to continue promoting Prosper and encouraging my readers to get involved and help me out. However, for the time being, I am no longer offering advertising as an incentive for signing up.

If you are looking for a place to get a loan or if you want to get a good return on your money, you should check out Prosper. If you don’t need a loan or have a chunk of money you are looking to invest but want to help a fellow blogger, just join and invest $50.00 you will get your money back with interest and we will both get a $25.00 bonus!