It was very first time i hold the Tx in my hand to check the servo response , but i reallized that , the servo was vibrating discontinuously .It started vibrating from beginning when i powered the Rx n stopped after a short interval of time and then again started vibrating when i moved the stick , it again stopped n.....
Then i replaced that servo with another similar one, but again i experienced the same problem .

I didnt understand the xact reason behind it , so i jst wanto ask whether it is servo fault or .....?

The servos, i was using are :

http://www.hobbyking.com/hobbyking/store/__7476__Turnigy_1370A_Servo_3_7g_0_4kg_10sec.html



thank u .....!!!

- saurab.

should have read the review before buying, every one who bought this are saying they are bad servos.  here area few comments


"Well, don�t know where to start. Ordered 5 of those and found only 2 usable. Other ones have extremely chunky movement and just won�t centre. Used Y-cable to compare movement and they just never return to same neutral when I centre stick on my radio. I seems like they are manufactured on at least 2 deferent lines, a good and an bad one.

Buying those is very much of a gamble, but if you get lucky you might get a few really good ones. After all,
      
DAVID LECLERCQ

I bought 7 of them to put in foamies. I've mounted already 3 of them and when turning my radio on to check the plane setup, I've noticed a very bad neutral and wide range of my stick movement without any action of the servos. And that for all servos ! I would have to make correction everytime when flying. Very cheap but bad quality. Real weight is 4.7g. I don't even dare to fly with this setup and will change all of them by 3 hextronic 5g (6.4g in real), much more reactive !

Not very useful, do not centre well, had to replace all of them in my foamy
   
Derku

The actual weights I measured from 3 I bought are:

4.40g, 4.39g, 4.36g => 4.386g-ish

Note this is without servo arm and screw.

The performance is also a bit jittery and the rotation is low about 45 degrees(total). Torque is accurate however the servo response seems slower than 0.10sec and a bit laggy too.

I agree with other customers comments to not sacrifice quality for the postulated weight - I recommend HXT500s intead. GL.

cheap servo's, strong enough for small parkflyers and indoor planes.

But they aren't very precise. I didn't really expected that but for the price they are OK.

You better buy HXT500."

It was a bad buy. they are Bad servos.

PS
What Tx are you using ?

There could be other reasons too (although in this case seems a poor quality servo is likely)

Battery not fully charged
Poor/loose contact
Metal to metal interference (pushrod)
Damaged lead

etc.

I have these servos  http://www.hobbyking.com/hobbyking/store/__662__HXT900_9g_1_6kg_12sec_Micro_Servo.html
, and i also faced same problem.

HXT 500 can be jittery too.
Just use another BEC for servo power supply or replace ESC totally.

First interchange that servo in other channel and search if the servo is the faulty one or the channel of receiver. Then only you can take decision that servo fault.

If some other servo also jitter, you need to check Rx or ESC.

If throttle is OK, then just use an BEC/SBEC additional for servo power or an receiver pack.

Thanks

Try moving the receiver away from servo. If you are using it for f*v move your video rx away from the servo.

@ augustinev : sir im using the following Tx

http://www.hobbyking.com/hobbyking/store/__16239__HobbyKing_HK6DF_2_4Ghz_FHSS_6Ch_Tx_Rx_Mode_2_.html

@ sanjayrai55 : no doubt, the battery was fully charged
                      loose contact and Damaged lead was not an issue , the servos n radio both r new.
                      I didnt understand "Metal to metal interference (pushrod)" , can u please tell me?

@ KALYANPRODHAN  : sir i tried that option of interchanging the servo in other channel also , but...

Finally i reached at the conclusion that , the servos are of bad quality , but still i wll try it again n then wll take the decision of replacement ....


thanku so much friends ........!!!


- saurab.

Related... http://www.rcindia.org/electric-planes/servos-juddering-when-power-switched-on/

it could even be the Tx , how are other servos behaving ? read this thread and the links inside to get an insight into FHSS

http://www.rcindia.org/radios-and-receivers/difference-between-fhss-and-fasst/

http://www.rcindia.org/radios-and-receivers/interesting-article-on-2-4-g-and-the-diff-between-dsss-and-fhss/