Race Radio Antenae Options

Rprice

Well-Known Member
Scott that was definiatly a good sales pitch and that made up my mind on which radio too choose. although i have a few questions(I know nothing about race radios so these are some dumb questions) I volunteer at some MDR events and instead of having to borrow a radio everytime could i use a roadmaster too talk to them, #2 if i'am chasing for a team i could i just select their freq. without having to reprogram it? how long is the warrenty although i doubt ill ever break the radio or get it really dirty since its in a chase truck. Thanks
 

elcaprerunner

Well-Known Member
I was reading a post on the class 9 board and saw that TimHayosh posted that there is no modification to do to the Kenwood 271a to get race frequencies ( like the 261where you cut the W1 wire), is this true? Or can you have it tuned to use the right frequencies (151.xxx), like all of the other ones? And if it is true that the 271 can't be used, and also that the 261 is not being made anymore, what does everyone think about the Icom V8000? It's 75 watts and for sale on HRO right now for $140. ANd what needs to be done to get race frequncies, just re-program it?
 

Tim

Well-Known Member
"oh, 10-4 . Psshhhhhhhhhhh."
 

ntsqd

Well-Known Member
mods.dk doesn't yet list the 271 so no mod as of yet. There is a v8000 listing though. About 1/3 of the way down the topic is the pic and text to go with.

One guy measured after mod broadcast performance of the v8000:

144MHz 68W
146MHz 68W
148MHz 68W
150MHz 65W
155MHz 46W
158MHz 33W
160MHz 11W

Looks like you take a big hit above 150Mhz. A further post points out that the radio still draws the same current, so the difference in power is being converted into heat by the final amp. Translation: Long broadcasts ~@ 160Mhz = Smoked radio.

If the FCC catches you using a modified radio, I do not know you.
 

DMSRACE

Well-Known Member
IMHO, I would buy radios from the companies that support off-road and sell the RIGHT equipment...I went the HRO way and it is not all it is cracked up to be...when you modify the radios, the power goes down, it is illegal, and wait till you have to get them repaired....no shop will touch them... and they are not nearly as tough as biz band radios....you may only spend $200.00 now, but more than likely it will be junk in a year or 2...if you still want them, I have 1 ICOM 8000 and 1 Kenwood 261A I will sell too...
 

Wayne_Nosala

Well-Known Member
Thom, when that power test was done, the antenna
has to be re-tuned (matched) to the corresponding frequency.

An antenna tuned for 144mhz may be way out of reflected
match at 160mhz, this can adversely effect performance and even damage a radio.
 

ntsqd

Well-Known Member
DMS, the way race radios are currently used nearly everyone is illegal. This recent 'ramping up' in output power is sooner or later going to draw the attention of the FCC b/c of interference with legit users of the freqs. Someone from PCI posted a while back that PCI has licenced something like 1000 mobiles on, I imagine, the Weatherman freq. That's a great service to the dez racing community, but for what area ? If you're in North Carolina it won't cover you, probably won't cover you in Nor CA either, may not even cover you in Ridgecrest. And if you're not on the Weatherman freq then you're plain illegal unless you've leased the rights to that freq in that area from the FCC. Friend of mine works for a Co. that has 2m Business band handi-talkies on the plant. Two co-workers took them on a trip up north. They got booted off 'their' freq in Fresno; they were on the Fresno Ambulance freq.

Here's the link to the mods page: mods.dk
The only thing said about the above power output testing is this: "(US version measured on an IFR FM/AM 1600 service monitor)"
Whether that means that the 'antenna' was tuned for the freqs tested I do not know. I mostly posted the results to show that there is a degradation in output since the amp(s) are now also being operated outside their intended range. I'm sure that a clever person could tune those too. At some point you're doing it b/c you like doing it, not b/c it's the only way to get there from here.
 

racemedic

Active Member
Ok here is my opinion on this. You get what you pay for, now with that said. If a ham radio is all you can afford then yes it certainly is better than no radio at all. But if you hold off and maybe save a few more $$$ then get a commercial radio PCI, Motorola, Kenwood or whatever you will be better off. Commercial radios offer more usable options than any ham radio will. Things like scan options or remote audio thru an outside speaker. Ham radios offer scan features but it’s just that a simple scan feature. With most commercial radios you can set up a scan list and tell the radio what you want it to do. I have my radio set up to scan our main race channel and the Weatherman channel, but when there is radio traffic on our main channel and I’m listening to something on the weatherman channel it will jump over to our main and I can hear what is going on, you can't do that with a ham radio. Also you could look into used commercial radios. There are many older radios out there that have been traded in due to an upgrade. The radios that I use are Motorola Spectra’s, 128 alphanumeric channels and up to 110 watts and I also have an options box wired up to it that gives me the ability to run the audio to an outside speaker, so when I get out of the truck all I do is hit a button on the control head and I can still hear what is going on. This setup cost well over $2500 15 years ago when it was purchased new by some police dept, but I got it used for less than $300 and it works perfectly. If you look around and know what to look for you can get good, reliable radios for not a lot of money. If not give PCI a call and see what they have. I know a lot of you here run ham radios and don’t have any problems with them and that’s fine. I’m a ham and yes I do run a ham radio in my truck, but I also have commercial radios for use out at the races, they just flat out work better. If I would have to pick only one radio to put in my truck for out at the races it would be a commercial radio.

As for antenna… location, location, location. Just like Scott said, drill a hole and permanently mount it in the center of the roof it will work much better and in the long run will last longer and you will be happier. Just like with radios, pick a quality antenna like Antenna Specialists, Antenex, Maxrad and the like. Spend a few extra dollars if you can and you will be much happier in the long run.

Just my .02 but I hope it helped
Bob
kc6tjk
 

jeff

Moderator
Kenwood TM-271a - Expanded Frequency Mod

1. Remove plastic cover from the radio.

2. Remove rubber washer that goes around the top of the radio.

3. Remove eight screws holding the top shield.

4. Locate and remove R119 (this is clearly marked) which is close to IC252

5. Re-assemble. The radio automatically resets itself.

Tips: The "119" is located in the mid/upper left with the radio facing you as you would use it.

Aloha
 
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