Radio question

[Eirewolf]

Does anyone know of any race radio setups out there? I have found a few, but i don't know exactly what to buy.

[NASA Jim]

I've been searching for a radio system for a while- even watching eBay. But, it looks like the best deal is Sampson Racing starter set: http://www.sampsonracing.com/sampson_racing_new/rr_systems.htm

 

I've looked to see what other people on my region are using and the Sampson seem pretty popular. One of those purchases I have yet to make however.

[Eirewolf]

thanks, that is what i have also found so far. ebay has pretty much nothing that i can ever find, guess i'll get the sampson rig then, thanks!

c.

[CaptainWho]

The real problem with radio selection is that it depends quite a bit on the tracks you'll be running. At tracks on flat terrain with relatively small amounts of vegatation, a pair of cheap FRS radios putting out 100mW are fine. In hilly or heavily forested terrain, they may not be. At Road Atlanta, for example, you'll probably need a couple of watts of power to reach from the pits/paddock (down in a hole) to the back of the track (behind and below a ridgeline). Your best bet is probably to talk to people at the tracks you run and see what they're using and how it's working out for them.

[KraziLee]

Try Motorola GMRS Talkabout radios with a Sampson Racing car harness, helmet and crew system. The radios have a range of 5 miles and the Sampson Racing pieces fit and work perfectly. It give excellent clarity, volume and range. I've used it at Sears Point, Buttonwillow, California Speedway with no dropout zones.

 

Two radios cost only $85.00 which is a whole lot cheaper than the Tekk or Kenwood radios. The whole setup for driver (helmet and car harness including radio, PTT, Ear Buds, Noise Cancelling Mike),and one crew member (Radio and headset) only cost me $300.00! A whole lot cheaper than $1200-$1400 systems.

 

Hope this helps!

[924RACR]

We've been working on putting things together using FRS/GRMS radios. The hardest part is working up an external antenna. But for the helmet setup, try a Motocomm system (motocomm.com). They sell the speaker setup, but it includes a PTT and separate mike (velcro into helmet) for only $60. Far cheaper than the Sampson setups, IMO. From what I've heard from others who've already tested them, there are NO issues with volume, even in spite of not having earbuds.

 

I've also heard that you can buy the noise-canceling or noise-reducing earbud speakers from Radio Shack for I think about $20, replace the foam with good earplugs, and have homemade earbud speakers for race use for far less. Just have to wire in a connector to plug them in, then.

 

I plan on using this setup with FRS next race weekend...

[Jim P.]

What we have found so far in the SE - this year to be exact!

 

1) GMRS works much better than FRS

 

2) UHF/VHF works better than GMRS when distance is a factor

 

Nothing works well at Road Atlanta or Snowshoe Mountain without a repeater.

 

We have found that with headsets/earplugs/etc. you can successfully use GMRS radios at about every track BUT Road Atlanta - too many hills/valleys.

 

The only potential drawback with GMRS radios is that so many people have them that you could end up with many people on the same channel(s).

[SRC/SampsonRacingComm.]

Folks thanks for the kind words... we do our best to give you the best quality Racing Radio System for the $ and one that we know works and works well!! We are also proud to be again supporting the 25 hour enduro and all the teams http://www.nasaforums.com/viewtopic.php?t=3297

 

The problem w/ the new GMRS radios is that you can not add an external antenna kit but if mounted properly they will do a fine job for you as a starter system and you can always upgrade at a later date... as long as you get top of the line products to start w/

 

Note: A proper 5 watt mounted UHF system will work at any road racing track in the US... that means the you must use an external antenna, ground it properly and run the car harness system well away from power sources. We do consulting and have a great reputation with major race teams throughout the US trouble shooting racing radio systems... FYI-its always because they were set up improperly... you should be able to talk w/ your crew at any time and any point on the track w/o static

 

Also- please note that speakers in helemts are not the ideal set up, unless your running in the Miata type dB range 96 or lower!

[Hal]

Shawn,

 

When you guys do a pro racing install do you use a directional wattmeter like a Bird and tune the antenna for the actual frequencies used? Anyone run over 5 watts?

 

Regards

-Hal

AI West #46

[924RACR]

First, the disclaimer - no objections to the higher priced pro setups, just can't justify the cost.

 

The results at our little bull-ring showed that range was no issue throughout (as expected) the track with the FRS radios. Volume in my sound-busting IT car (gonna do a new exhaust next year just to consistently meet sound and reduce driver fatigue) was not an issue with the helmet speaker setup. No idea what db ratings inside the car were, of course, but I do know my car's usually within 5db of the sound limits on the marginal wet days. Definitely more noise than an SM.

 

Clarity was the major limiting factor, no question. Idling on grid, it was okay, but weak; once we got going, however, it was mostly noise - in both directions. Real bummer. Not sure what the major source of the loss of clarity was. I suspect the next step will be to try the GRMS radios. I might also get around to putting earbuds into the loop as well.

[SRC/SampsonRacingComm.]

Hal- most UHF antennas come tuned and thus work much better than VHF antennas, so that's not much of a problem. The only tuning we really get into is when were setting up repeaters.

 

5watts is the most in a hand-held set up. Base and mobile units can be upwards of 125watts.

 

924racer- you are having RF problems

1. look at more power (2/4 watt GMRS radios only $65)

2. make sure to run the car harness away from any power sources

3. move the radio to other spots in the car

4. make sure the duck antenna is out in the open

5. YES- ear buds will make a difference, your spotters voice will be in your head, not trying to be heard through the eng and tire noise.

 

There is no reason that you should not have great communications

Hope this helps...

[924RACR]

I was at the Glen this past weekend, running the SCCA 3-hr Last Chance Enduro (which I can feel comfortable mentioning here, since we're not paranoid like some areas of the "other" club are... ) and have some more observations to relate about cheap radio solutions.

 

First up, we were using GRMS radios there. Range was surprising, given the elevations; we were able to transmit/recv to the back straight, though the boot was a stretch. Unfortunately, I know this because of poor circumstances.

 

Intelligibility was crap, no question. I only experienced the car-to-crew radios, so perhaps the pit-to-paddock radios were OK - seemed like they were having good success communicating back and forth. Have to verify this with my crew chief. But in-car was virtually not understandable, certainly not at speed, for me. However, once I blew up (probably headgasket) and parked at the beginning of the bus stop, I was able to communicate back and forth to the crew fairly well and explain the status.

 

So clearly we had issues with radio/ignition interference, at least in that car.

 

Another very amusing thing that was noticed... I did not route the wire that was the RPM pickup for my AIM data/dash system, and it ended up going RIGHT BY the radio box - DUH! Whenever I keyed the mike, it sent my shift lights NUTS on the dash. Clearly massive interferences there. Wasn't too happy about that, but too late to fix. Speaking of interferences, it is an interesting contrast back and forth between the ignition and the radio; I wonder how much was caused at each end.

 

Just proves the point about how you really do have to do your homework and test this stuff out thoroughly. I still don't quite see the benefit of the more expensive radios, other than range as a function of power, since both are so susceptible to interference. These radios all seem about as signal-tight as a hospital X-ray machine is radiation-tight...

[John A]

Try Motorola GMRS Talkabout radios with a Sampson Racing car harness, helmet and crew system. The radios have a range of 5 miles and the Sampson Racing pieces fit and work perfectly. It give excellent clarity, volume and range. I've used it at Sears Point, Buttonwillow, California Speedway with no dropout zones.

 

Two radios cost only $85.00 which is a whole lot cheaper than the Tekk or Kenwood radios. The whole setup for driver (helmet and car harness including radio, PTT, Ear Buds, Noise Cancelling Mike),and one crew member (Radio and headset) only cost me $300.00! A whole lot cheaper than $1200-$1400 systems.

 

Hope this helps!

 

I apologize for resurrecting an old thread but I'm looking for a radio communications system. After reading this entry from krazilee, I'm certain that even I can communicate with my crew with out breaking the bank. Its been a year or 2 since the last posting and I was wondering if anyone has created a better solution since then?

 

John Almazan

[John A]

Anybody? Don't make me start a new thread!

 

John A

[Eric J.]

The GRMS radios that you can buy at Best Buy and such places are actually quite good. The set I have even has voice activation and came with a nice headset that I suspect would fit pretty nicely under my helmet. The potential, then, is that I could have the thing in my pocket, the headset on with voice activation and have a completely hands-free link (on my end, anyway).

 

And they're inexpensive.

 

Mind you I haven't tried this yet, but it shouldn't be tough to pull off.

[white_2kgt]

The GRMS radios that you can buy at Best Buy and such places are actually quite good. The set I have even has voice activation and came with a nice headset that I suspect would fit pretty nicely under my helmet. The potential, then, is that I could have the thing in my pocket, the headset on with voice activation and have a completely hands-free link (on my end, anyway).

 

And they're inexpensive.

 

Mind you I haven't tried this yet, but it shouldn't be tough to pull off.

 

Voice activation in a loud ass racecar? Good luck w/ that, lets us know how it works.

[Eric J.]

In a "loud-ass race car" voice activation will be problematic. In a car that won't get your track closed down for noise violations it might be marginal. In a comparatively quiet car (like mine) it stands a fair chance.

 

But pushing a button isn't that hard, either.

[white_2kgt]

In a "loud-ass race car" voice activation will be problematic. In a car that won't get your track closed down for noise violations it might be marginal. In a comparatively quiet car (like mine) it stands a fair chance.

 

But pushing a button isn't that hard, either.

 

Also you have to worry about the guy next to you with loud exhaust. I'd go push button if at all possible.

[John A]

So GMRS radios are recommended. As far as the car harness, antennas, crew headset, helmet set, etc---would you go sampson or something else?

 

John

[Tom A]

I use a setup with Midland 5W GMRS radios and a MotoComm helmet kit. It is designed for motorcycles, but the cords are long enough to work in a car.

 

https://www.rflimited.com/ShowProduct.asp?productID=8&NodeID=c2

 

I fabricated a radio box out of aluminum and foam, and riveted it to the inside of the driver's door with the antenna sticking up in the window, so it has a line of sight out of the car, with the PTT button on the seat near the shifter.

 

Results have been mixed:

 

A couple times it has worked wonderfully, and we have had coverage for most of Thunderhill, even had some car to car comms. A friend used our setup in a different car at Buttonwillow, and also had excellent results.

 

Other times it has worked poorly, with the usual problem the driver can't transmit out of the car, but can receive. We have tried moving the radio to different locations inside the car, without much change. I think it may be interferance from the cars electrical system, because it works fine in the pits. If this is the case, I would think it would improve if if the radio is isolated from anything hot in the car, and this hasn't made any difference, even with the radio mounted a few feet from anything powered.

 

If anyone has any ideas I am all ears.

[Eric J.]

I fabricated a radio box out of aluminum and foam, and riveted it to the inside of the driver's door with the antenna sticking up in the window, so it has a line of sight out of the car, with the PTT button on the seat near the shifter.

 

That sounds like a slick idea. I think I may try something similar.

 

Other times it has worked poorly, with the usual problem the driver can't transmit out of the car, but can receive.

 

That's generally not a location problem, since if you can close the link in one direction you should be able to close it in the other direction from the same site (assuming similar radios on both ends of the link). If you're transmitting the same power as the other guy it's not a propagation or location problem if you can hear but can't transmit. It's more likely to be a problem with getting the radio to key or with the mic-radio connection.

[Boudy]

That's generally not a location problem, since if you can close the link in one direction you should be able to close it in the other direction from the same site (assuming similar radios on both ends of the link). If you're transmitting the same power as the other guy it's not a propagation or location problem if you can hear but can't transmit. It's more likely to be a problem with getting the radio to key or with the mic-radio connection.

 

Actually, your thinking is correct but the car and pit wall are not equal. The driver suffers no less than a 6dB signal loss (75% loss) leaving the car. Hense, there are areas of the track where he can't reach pit wall but pit wall can reach him. Tom's idea is well founded to get the radio as near to the window as possible. However, the cure to his problem is probably an external antenna. Unfortunatly, I think he's using GMRS/FRS radios and the FCC prohibits it.

 

GRMS/FRS radios are fine if you understand the limitations. As mentioned above, you can't fix an external antenna to them so you car will suffer in some cases. Also, only 8 of the 22 channels can be legally used without filing an FCC form 605 for a license. Then there is the privacy codes... This expands privacy, not capacity. You will still only have 22 channels, period.

 

Boudy

Edited to remove link.

Edited July 6, 2006 by Guest

[rabbit_diesel]

Other times it has worked poorly, with the usual problem the driver can't transmit out of the car, but can receive. We have tried moving the radio to different locations inside the car, without much change. I think it may be interferance from the cars electrical system, because it works fine in the pits. If this is the case, I would think it would improve if if the radio is isolated from anything hot in the car, and this hasn't made any difference, even with the radio mounted a few feet from anything powered.

When you wrote "... because it works fine in the pits.", did you mean when the engine is not running, as opposed to the radio performance when the engine is running? If so, (and assuming a spark ignited engine, and assuming that the radio works equally well whether it is in the aluminum box or not) I would consider that the trouble might be radio frequency noise coming from the ignition system. For instance, are you using solid metal core ignition wires, rather than the other type which suppresses radio frequency noise?

 

Will

[SRC/SampsonRacingComm.]

easy test- take the radio out of the car and start the car. bring the car up to RPM speed and then move the radio back towards the car...

 

Does the radio start braking up when you move towards the car???

 

YES- you could have a ground or ign problem or you need to get higher power (5watt) radios.

 

No (its still a problem)- are you running race tested equip, ie, shielding in car harness, noise cancelling helmet kit w/ transducer ear buds, does your crew headset have a noise cancelling mic, etc?

 

FYI- A set of 5 Watt GMRS radios should run you about $70 and you can add professional parts that are built for racing communications all for under $500 total. See the Starter System below for an example- Also, look at the "The Expert" for a super value on a long track system only $799

 

http://www.sampsonracing.com/sampson_racing_new/home_f.htm

 

Word of Advice... make sure you understand the limitation of what you are buying and wheather it will work properly for your needs... If not, it might be just wasted racing funds that could of been used in a much better way... like beer for the crew

[Eric J.]

That's generally not a location problem, since if you can close the link in one direction you should be able to close it in the other direction from the same site (assuming similar radios on both ends of the link). If you're transmitting the same power as the other guy it's not a propagation or location problem if you can hear but can't transmit. It's more likely to be a problem with getting the radio to key or with the mic-radio connection.

 

Actually, your thinking is correct but the car and pit wall are not equal. The driver suffers no less than a 6dB signal loss (75% loss) leaving the car. Hense, there are areas of the track where he can't reach pit wall but pit wall can reach him.

 

Not true. Propagation is symmetric (i.e., if the transmit powers are equal the receive powers will be equal in both directions on the link). Interference, however, is generally not symmetric and can affect sensitivity differently on each end of the link. I think the other posts on sorting out interference are probably spot-on. It's either a connectivity problem (with the mic or PTT switch) or an interference problem. Shielding interference sources in the car will probably help, but these things can be tough to sort out.