I have a brushless RC10GT running a Mamba X and a Sanwa MX-3 75MHz FM tx/rx. I get bad glitching if I go more than 200 feet away. I can feel some minor jiggles in the steering as close as ~80 feet depending on the direction the car is pointing. I have tried everything including glitch buster caps and ferrite rings, to no avail.

I've researched it and looks like 2.4GHz might fix this 100%. Further research shows the Spektrum DX5C with 6100AT AVC receiver is the best value for $150 or less. However after reading the DX5C manual, it also looks like I'd need to upgrade my HS645MG steering servo to a digital variant.

Can anyone confirm this is the right course of action to make this thing driveable? Thanks!

if your upgrading radio. run it and see if servo wont respond to your system..now you know what old rc racers went thru for years .(I know I did)

Mamba is well known of using a very bad BEC causing glitches. If that is also the case with your issue then a 2.4HGz TX/RX will not help.

Not all 2.4ghz systems require digital servos but it looks like the receiver with the built in AVC system does require it as it looks like it could overheat the servo otherwise.
Another version of this with a more basic receiver should be more compatible with older analog servos. I have AVC on my radiolink radio and personally always turned it off but it was a cool feature to test and play with.
https://www.spektrumrc.com/Products/...ProdId=SPM5100

For glitching my guess is that a 2.4 radio would fix this. More then likely i would guess that the older crystal might be causing you problems, if there is something like a screw vibrating on the metal chassis, any near overhead electrical lines, the neighbors microwave, or just electrical noise from the brushless systems normal operation can cause problems on old AM/FM systems.

Even a cheap $50 2.4 ghz would be a huge step up when dealing with glitches and signal strength. Otherwise the spektrum system you have is great and even if your servo ends up compatible there are lots of 30 dollar servos that will do the job better and would be great upgrades.

You could try to do a small receiver pack with AA's powering the receiver but in 2020 there is no reason to run a FM radio anymore.

so if it is your mmx bec then a simple ubec will fix. any where from $3 to $25+
or you do as you said replace that 75mhz with a 2.4ghz (is what id do asap)
as said also you can replace that servo either b4 or after you test with another servo of digital type,,
Ive seen motion detector alarm systems mess with 75 and early 2.4. also seen many other things interfere with 75

When the truck was still nitro powered, I had glitching with this radio caused by a simple temperature monitor/failsafe device. But it worked perfectly once removed. As soon as I switched to brushless all hell broke loose.

Alright sounds like 2.4 is the first step. I really like having end point adjustment and expo, so this rules out a lot of the cheaper radios and puts me in the MX6/DX5C/3PV range, and the DX5C looks like the best value.

Does anyone know the technical reason why analog servos will overheat with AVC?

Your definitely are looking at the right radios for your price range then. There are some cheaper lesser marketed radios that have all those features like radiolink and flysky but in general if you want more factory support and warranty coverage then the big 3 is a great place to start.

Could be somehow that the motor noise/emf is causing the bad signal. I dont think its a power issue as it sounds like everything works up close well enough and its a range issue glitch but the older analog servos especially something like a 645 could be enough of a current drain on the BEC to be a problem to somehow shorten the range.

Don't know why Spectrum says it could overheat but my guess is the frame rate on how fast that receiver will update servo position is faster then a analog servo should be updated. I think the older more compatable receivers have a slower framerate - goto page 10

https://www.horizonhobby.com/pdf/SPM5100-Manual-EN.pdf

As above, the analog servos can overheat from the higher framerate.
The other brands also recommend sticking with digital servos in the higher framerate modes, usually >100Hz.

I suspect that switching to 2.4GHz will fix the issue, personally I'd stick to Sanwa or Futaba (both offer a mode for non-digital servos, then you can switch to faster modes if/when you upgrade servos), but the Spektrum should be OK too. I've seen range issues with cheaper AM/FM radios in certain areas. If you have a friend with some 2.4GHz gear you could borrow first that'd be good, otherwise I'd see it as something you'll probably want to do eventually anyway.

I'd check out the Sanwa MT-S with RX-482, I'd choose it over the Spektrum:
http://www.rcmart.com/4channel-radio...ml?cPath=36_47
Priced similarly, well-renowned receiver, and has a normal mode for analog servos + faster modes for later.

Thanks for the info. I only have 1 r/c friend so I will see if he has a radio I can test.

The one thing about the Spektrum that I like is the AVC system, which no other radios seem to have and seems like kind of a game changer to me. Is the Sanwa recommendation just brand preference or does the MT-S offer more over the DX5C that I am missing?

AVC is a drivers aid and is illegal in most forms of racing. You're not likely to find it on the racing focused brands.

I have a DX5 Rugged that I use with my crawlers and U4 rigs. For anything that’s fast but hard to control AVC is a huge help but it takes a decently fast servo to get the most from it. All of my race cars run off a Sanwa M17 but it’s way overkill for what you need.

Yeah I'm not racing so not concerned with that. Makes sense though.

I always wondered about that. I would think the AVC needs a fast servo to respond quickly but they make no mention of it in their documentation.

I think alot of people here (including myself) recommend Sanwa/Airtronics here because they are great racing radios and alot of people like the way they feel in their hands. I see lots of Spektrums at club races and they seem like great all-around radios as well.

It seems like you have done your homework and with the AVC being a feature that you want to try I think its a great option. Sanwa and Futaba do not have this feature built in so you would need another box and even those gyros only adjust steering whereas i here the AVC on the Spektrum might do something with the throttle as well.

Spektrum might be alittle less expensive also with more models as I think they have some more budget friendly receivers but I think every manufacturer is making good money on there receivers!