BigRedBee transmitter

[Windeavor]

Just received the 70cm BRB beacon transmitter. Charged up battery via USB which only took about 1.5 hours. Installed software on computer, powered up unit and connected USB interface. Computer defaulted USB serial port to COM 5. Software for BRB only goes to COM 4 so used COM 2 which was available on my computer. Selected "Read" and the software downloaded all the data from the transmitter. Very cool! Greg even configured my HAM license onto the transmitter prior to shipping. Made some changes and selected "Write" to send data back to the transmitter which it performed successfully.

Once powered on the transmitter transmits my HAM license data via Morse every few minutes to identify who is using the transmitter which is required by FCC. I left the transmit interval and length default but changed my broadcast frequency a bit. Every 5 seconds my Kenwood TH-D72 receives the signal. My best reception is -.025 offset from the programmed freq. So transmitter is configured to broadcast at 135.500 MHz and I hear it best tuned to 135.475. Programmed my radio to step up or down .005 MHz on every click of the knob for finer tuning. Pic below shows the USB adapter connected to the transmitter and is charging the battery. Optional SMA antenna connected to transmitter. The USB board disconnects from the transmitter before deployment time. Transmitter is super light weight and very compact.

Took BRB transmitter to the park and set it up as far away as possible. With a 7 element Arrow 70cm Yagi antenna on the Kenwood radio I set the squelch wide open and tuned in 135.475. Came in loud and clear. Turned the freq down until the radio was just able to detect the transmitter signal on the signal meter. This made finding the strongest signal and direction easy. Walked toward strongest signal and as the transmitter gets closer the signal meter increases. Turned the freq down again until it just registered and continued this method until on the target. My son took the transmitter and hid it a couple more times, and using the same technique had little trouble getting within a few feet of the transmitter itself. Works great and as has been mentioned is actually a fun challenge, but most importantly will be a huge asset in recovering way gone rockets.

 

[troj]

They are indeed handy devices!

If you've never done fox hunting/tracking, put the tracker in a rocket you're fairly certain you won't lose, and start practicing on "finding" rockets that way.

It's definitely an art that takes time to develop.

-Kevin

 

[dixontj93060]

You will find a lot of BRB fans here. Wouldn't fly without one!

 

[BEAR]

I purchased a Telemetrum for my first transmitter/tracking device. Since I live just a few miles south of Cheyenne, Wyoming, I went to Arrow and met them. A couple of great guys. While I was there I purchased the 7 element Yagi also, but I also purchased their clamping mechanism so that I can clamp my Yagi to a pole. I also asked them to make me a 20' antenna cable that had the fitting for the antenna on one end, and the compatible fitting on the other end so that I can attach this to my Yaesu handheld without using an adapter. What this allows me to do is to attach my Yagi to the top of either my 12' or my 24' telescopic painters poles. Now I can listen in from a much greater distance, effectively increasing my range. I can even put it through the sunroof on my SUV and listen in as I rotate the pole and drive, to track down my bird. I just pass this on to help others in their endeavors.

I am also considering getting a BRB because as I understand it, they work on APRS. If that is correct, then I am presuming that if I call up www.aprs.fi on my smart phone, I will be able to track it that way also. Has anyone tried this method?

 

[troj]

I am also considering getting a BRB because as I understand it, they work on APRS. If that is correct, then I am presuming that if I call up www.aprs.fi on my smart phone, I will be able to track it that way also. Has anyone tried this method?

The BeeLine GPS uses APRS, and comes in two flavors -- 70cm and 2m. If you want to use that website, you'll need the 2 meter version, in addition to being near a gateway and having your transmitter on the right frequency.

Whether or not your plan will work depends on factors that will require a little research to verify.

I use a BeeLine GPS with a Yaesu VX-8GR, which decodes the APRS packets and tells me which direction (and distance) the transmitter is. Kenwood also makes a radio which will do the same.

-Kevin

 

[BEAR]

Kevin,
I have the Yaesu VX-7R. Getting to the correct frequency should not be an issue. What I found interesting with the website (www.aprs.fi) is that it gives me the location of all the transmitters in my area. As I close in on the map so that my search area is smaller, it will get down to the co-ordinates. I would like my transmitter to show up on this website. So my thought is that since I can get GPS and I can get 3G/4G at both of our NCR launch sites, I can pull this up on my smart phone (DROID) and get the co-ordinates from that, pull up the compass app, with GPS location, and walk right to my bird, just as I can do with the Garmin dog collar. Except that I can use my phone, and I can use my Yaesu and my Yagi as a secondary system. I like to have many choices and having as much redundancy as I can, so that when Professor Murphy decides to drop in and give a surprise exam, I will be ready. His laws are always in effect, just like physics and GOD.

 

[troj]

The website you referenced is dependent upon a network of repeaters that pick up the APRS packets from beacons and make them available to the system that feeds the website. If there's not an appropriately configured repeater in range of your launch site, your beacon won't appear on the site.

-Kevin

 

[Windeavor]

Greg at BRB recommended the 70cm for my rockets which use deployment electronics. The 2m is much more powerful and could cause issues with the deployment electronics. You don't want deployment electronics going off in mid flight or failing due to overpowering RF interference from recovery electronics. Kind of defeats the purpose...lol.

 

[Worsaer]

You might also be interested in the offset attenuator from Arrow. I use the identical configuration of transmitter and radio that use, also with the attenuator. They make a nice combination.

 

[Windeavor]

Having not used an offset attenuator what is the benefit of using this device over manually offsetting the frequency via the tuning dial on the radio? I am able to program my radio to step in .005 incraments via the tuning dial which seems to work well, but hay if there's a distinct advantage to the Arrow attenuator I'm all ears.

 

[Worsaer]

When hunting for the transmitter at relatively close range, the transmit signal can overwhelm the receiver, making it difficult to determine directionality. The idea behind the offset attenuator is to tune to an offset frequency, then attenuate the signal to just the minimum required to receive it. When out in wide open space where you can see the rocket on the ground from 100 yards, it's likely not needed. If it drifts into heavy brush or ground cover, this can help you pin point directionality with much greater precision. I too am still getting the hang of it, but like what I see so far.

Looking at your location, do you fly with LUNAR at Snow Ranch, and/or perhaps with TCC?

 

[troj]

An offset attenuators can be handy, but you can do it without them. Turning the radio off frequency, holding the antenna just above the ground, shielding it with your body, these are methods that work to attenuate the signal, as well.

-Kevin

 

[JimJarvis50]

I use the Arrow attenuator and I think it provides some advantages over offsetting the frequency. The main area where there is an advantage is getting the best direction of a rocket in the air. I have found that with the BRB equipment, I have to use the signal strength meter, rather than the beep volume, to get the best directionality. I can easily use the attenuator to place the strongest signal at about half scale on the meter. As the distance to the rocket changes, it is easy to fine tune this with the attenuator. The frequency adjustment route doesn't allow this level of resolution, but it works fine once the rocket is on the ground.

It's taken me a while to get used to using the signal meter. I used the Marshall equipment for many years, and with that equipment, the beep sound worked just fine. With the BRB, you have to use the meter, which means you have to be able to position the signal on scale.

Jim

 

[Windeavor]

Yes I go to Snow Ranch as well as TCC near Fresno.

 

[Windeavor]

Jim as you pointed out I only use the signal strength meter as well. Once I offset the radio enough the signal meter is the only way I am able to detect signal as the audiable tone is long gone. I can basically turn the volume all the way off and just work the signal meter and adjust offset. It works very well on the ground but in the air I'm sure will be a new challenge.

I contacted Arrow and here is what they had to say about their attenuaror:

"The offset attenuator solves a problem. When you get close to a transmitter the signal is received through the body of the handheld radio and swamps the s meter no matter what you do. The offset attenuator allows the radio to be tuned off the transmitter frequency so that can not happen."

 

[JimJarvis50]

Jim as you pointed out I only use the signal strength meter as well. Once I offset the radio enough the signal meter is the only way I am able to detect signal as the audiable tone is long gone. I can basically turn the volume all the way off and just work the signal meter and adjust offset. It works very well on the ground but in the air I'm sure will be a new challenge.

I contacted Arrow and here is what they had to say about their attenuaror:

"The offset attenuator solves a problem. When you get close to a transmitter the signal is received through the body of the handheld radio and swamps the s meter no matter what you do. The offset attenuator allows the radio to be tuned off the transmitter frequency so that can not happen."

Yes, you actually read the attenuated signal 4 MHz higher than the transmitter frequency (not 0.05 different though). I wasn't aware that it solved the problem of reading a strong signal through the body of the radio. That's helpful.

My rockets often land several miles from the launch point. It's essential to have a reasonable direction while the rocket is in the air. Otherwise, the search area justs becomes too large. I find the attenuator easier to use for this than changing the receiver frequency.

When the attenuator is on, it doesn't affect your ability to receive the unattenuated signal on the transmitted frequency. This is helpful for me because I typically receive a BRB gps transmitter signal on the "B" channel of my radio (i.e., the attenuated beeper signal on the "A" radio and the gps on the "B" radio). The gps signal is read unattenuated.

Jim

 

[JimZNJ]

I have the 70cm Big Red Bee transmitter (beacon). Since my HT is on the fritz I have been using a scanner for a receiver. I have the Arrow 7 element antenna and the offset attenuator. The attenuator is a recent addition and a big help for me, especially since the scanner is quite susceptible to leakage through the case. I like the ability to continuously adjust the amount of attenuation to just the right level for tracking.

Without that level of adjustment I don't think I would have found my rocket when it landed recently in very dense 7+ foot high weeds. I was able to get a reliable heading on it until I was just feet away and finally spotted it and could hear the sonic locator I also flew on it. Maybe I got lucky, but that incident tracking a rocket through weeds taller than me really sold me on the value of a tracker. The attenuator definitely helped in this case. There is not much I don't fly now without my BRB transmitter.

Jim Z

 

[degreaser]

If you need a quick and dirty antenna, build the wa5vjb "cheap yagi". I use 1/8" TIG rod for mine.

View attachment cheapyagi.pdf