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Discussion Starter #1
I'm hoping someone can help clear my confusion. I'm looking to get back into RC after a 20 year stint. I've come across an old AM Futaba Mag Jr. I've also come across a car set up with brushless. I can't seem to find for sure if this combination will work together. Before a I take the plunge, can anyone clear this up for me?
 

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Discussion Starter #3
Kinda what I figured, but I started reading issues where BL stuff has high freq RF emissions that affect the AM and causes interference. Thanks for the clarification!
 

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Discussion Starter #5
Well, I got everything..hooked it up and it works! but it gets glitchy as HE!! from 100' on. So bad, I can't control the car. I have a couple other receivers I can try and drop down from 88MHz crystals to 70MHz and see what that does.
 

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Discussion Starter #7
aww..no way. Besides AM travels FATHER than FM or 2.4. Besides 100' isn't very far, 20 years ago I had AM radios (Futaba Mag) and could take my car wayyyyy down the street.

I should be more clear..with the frequencies in the AM band will allow farther transmission that FM frequencies. The lower the frequencies the farther they will travel. Not counting transmitter power, ect.
 

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Discussion Starter #8 (Edited)
After digging for a minute I see that regardless of AM or FM the frequencies are basically the same in 27MHz or 75MHz, the difference is just hte modulation. The ranges should be very similar. So I must have a hardware problem to track down.. :(
 

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What kind of brushless ESC have you got? Novak has some GTB models (designated "spread spectrum") that operate at a higher switching frequency and could cause problems with AM & FM. The standard models should work fine. I've also got another "off-brand" ESC that allows me to change it's switching frequency from 8kHz to 16kHz. You're supposed to use the 8kHz setting for 27 & 75 band radios. Probably the same as the Novaks, since it looks like they copied the GTB in it's design.
 

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Discussion Starter #10
What kind of brushless ESC have you got? Novak has some GTB models (designated "spread spectrum") that operate at a higher switching frequency and could cause problems with AM & FM. The standard models should work fine. I've also got another "off-brand" ESC that allows me to change it's switching frequency from 8kHz to 16kHz. You're supposed to use the 8kHz setting for 27 & 75 band radios. Probably the same as the Novaks, since it looks like they copied the GTB in it's design.
Thanks for the info. The ESC is a LRP Sphere. Best I can tell, anyway. There is no writing anywhere on it and I haven't removed the heatsink to look under it. Looks just like the Sphere, though.
 

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The AM radios after 1991 went to a narrow band frequency. With that I think today's AM radio's are much better then the pre 1991 models. You maybe getting glitches due to outside interference of devices that didn't exist 20 years ago. I remember way back then when you could only get crystals in even channels. Now you can get odd and even crystals. Those odd channels may cause interference for these older radios. Here's some reading that may explain better than I.

http://fatlion.com/sailplanes/radiohistory.html
 

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Discussion Starter #12
Interesting read. Thanks! My radio has 1991 stamped right on the back for it's inspection date. Soo..it can go either way I would guess.
 
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