aqeel200

Hi fellow RCer,

just want to get some info/experience if anyone had this problem with their spektrum SR3300T. I suspect my 3 units of SR3300T now is faulty with one barely working. I am baffled now...the SR3300T Rx is not cheap!

Spec of the SR3300T
TypeSM® receiver with integrated telemetry# of Channels:3Modulation:2.4GHzLength:1.60 in (41mm)Width:1.06 in (27mm)Height:0.58 in (15mm)Weight:.4 oz (11 g)Voltage Range:3.2–9.6V

I have been using my SR3300T for more than 2 years with 7.4V lipo via a 6.6V Rx regulators - no issues, all ports are inserted properly. no power source accidently goes into the telemetry ports in the Rx.

Note: 2 years without any problem.

a) i switched all my Servo from standard 6V servos to Savox HV servo (1268 - 25kg at 7.4V) connected via the same regulator @6.6V without any problem - close to 6+ months to 1 year.

b) what the heck - I use a HV servo but can only attain ~18kg for torque via 6.6V regulator..since the Rx SR3300T can take input of 9.6V, i can plug in the 7.4V lipo(10c - low discharge - same lipo as the Tx) direct into the Rx SR3300T and its internal electronics can take it..thus connecting a HV voltage would gives me the desired output voltage of close to ~7.4V to my Savox HV servo...all is well and i am satisfied with the torque produced from my HV savox.

c) suddenly - my satisfaction was shortlived..after several months (probably around 2 months), one by one my Rx SR3300T failed..the first one just went dead while my MT was in motion..the 2nd one also the same on another MT..but the 3rd one on a different MT - before it finally died, i manage to switched back to going via my Rx regulator - but the steering 'misbehave'..it was normal for about 1 minute then it slowed down...very little torque..i switched to a new servo - same thing. I tried 5 different servo, same result..i notice this - when the steering started to slow down, i turn it off, let the Rx cool down for about 5 minute, then turn it back on, the steering response is fast, then it started to slow down again...

my thoughts,

I don't think i did anything wrong in the connection as I am quite an experience RCer and understand basic electronics quite well. now the published specs of the SR3300T gives me some doubts as to what Spektrum claims to say that their SR3300T (and maybe any other Rx produced by Spektrum in the same series) input voltage is max at 9.6V but if the amount of voltage used as input is more than the normal 6.0V NiMH, the electronic circuit components (esp the on board BEC in the Rx) gets hot..it gets too hot over time that it failed..note: over time in my case is ~ 2 months of weekly use.

Does anyone has this experience before with their Spektrum Rx SR3300T.

now if want to claim this from Spektrum, damn, i dunno if spektrum(or Horizon) are going to replace it or otherwise..i have used it for more than 2 years, bought it of new from chopshop on ebay. I am a bit disappointed as what I did to use 7.4V input is within the specs of the 3.2-9.6V limit as published by Spektrum. If it cannot take 7.4V input, then it defeats the purpose of using a HV servo..note: I am assuming that it needs to be a straight forward input with the HV servo connectors, also straight forward input into the Rx..

I have seen some people did a HV servo reverse-bypass such that Rx input is via an external 6V BEC (or 6.6V BEC) but the HV power source (black and red cable) comes directly from before the external BEC..this still does not prove that the Rx can take more than 6.6V direct, ie a 7.4Lipo. There is nothing the in Spektrum manual that says 'if you want to use, more than 6V input, your connection must be done this way.....".

i dunno if Horizon is willing to replace my 3 SR3300T or otherwise. I am very disappointed actually as I cannot utilize my HV Servo to its full capability.

Appreciate feedback/ideas/share of experience from others.

wcalaker

iTrader: (1)

From what i understand the Savox Servos dont play nice with anything Spektrum. I bought a Savox servo cuz everyone was raving how good they were for being an inexpensive servo. $20 less than a fantastic Futaba (which spending the extra 20 in the first place would have saved me a lot of heartache).

I put my servo in and when i run it , it runs ok for about 2 minutes then it gets really erratic. Mainly it starts affecting the throttle and then it starts glitching the steering. If i let off the throttle for a bit it sort of resets itself but its a big problem when i am trying to race.


Theres also a lot of people at our track claiming that whenever a Futaba radio is turned on, it affects those with Spektrum/Savox combos.

hpikillr

iTrader: (1)

Ok.. Heat is your problem.. You are pulling to much current or amps..as your voltage drops(decreases) you current increases.. exponentially..either go with a better rx battery as in more mah or a larger voltage reg like 25 amp..

as for them replacing your cooked servos.. make a receipt that has a sale date so you are in the warranty period all is good .LOL

I know for a fact those servos will not take 6.6v for long nor will the last on 7.4 Ugh wrong voltage ITS 8.4V on a fully charged lipo..gotta keep those number right..
Try Radiopost servo.. I have 1 i have been running 2x a week for over a year now on 8.4v

sschultz

iTrader: (15)

Those(1268) are high voltage servo's! they can take it, check the specs. You need a glitch buster, Get one from member named (fix218). He sell's them here on rc tech....

easy peezy.... I think they cost like $10.24 shipped. DONE

Andy Koback

iTrader: (280)

The Savox are power suckers and cause brown-out with the Spektrum systems!!!

Nitro Ace

iTrader: (1)

"Does anyone has this problem with their Spektrum Rx SR3300T?"



Yes on my new losi 8 RTR, receiver was fine for break-in day......then second track day it stopped working after an hour of running. Now it won't bind....and pilot light won't come on. Uh-oh!