Bartech Focus Issue

[Leigh Hubner]

Hey All

 

Just a quick one while I am on the forum here. I have a BFD system which is just great and has treated me very well. I have had one problem which has popped up latley and always seems to happen as the word action is yelled! (starting to think the BFD is voice activated) I seem to be getting very fast random twitches in the focus motor. I have tried swapping motors and also tried swapping reciviers. Although rare it does continue to happen. Truth is, there could be lots of combinations of things to try, many I am still to tackle. The hardest problem I am having is making the problem occur so I can test it. Just when you think you find the problem, it happens again. Usually on set! I have recently been using new batts and they seem to be pumping out a higher voltage, up to 15.4 volts. Again this is a possible cause and I am meeting with a tech tomorrow for a good going over. Just thought I would bring it up here in case someone says, yeah, I had that and (insert solution) fixed it!

 

The problem started while working on an American TV series shot here in Australia a few months back. I was kinda nervous as it was working on this job let alone having this little problem pop up. I checked the website for the show we filmed.... not a good sign when it gets moved to 11pm on a Friday night!! Monarch Cove was the show... don't think there will be a series two!! Oh well, great experiance and I got to do some very cool shots so it was good for the reel.

 

Thanks in advance for any ideas on BFD problem.

 

Leigh Hubner

 

Australia

[Afton Grant]

Leigh,

 

Do the twitches happen when the transmitter is adjusted, or randomly when the system is supposed to be idle? I have experienced RF interference which will cause the motor travel to be jumpy. To fix, I just need to keep switching channels until I find a nice solid one. Every location has unique RF activity. There is no single perfect channel.

 

Best,

Afton

[JimBartell]

The most common cause of this is RF interference, often (but not always) from Modulus video transmitters. Try to isolate the motor cable from all other cables as it is the most susceptible to this kind of interference.

 

The battery voltage should not be a problem as the BFD will work fine up to 18V.

 

Jim "a little twitchy myself this morning" Bartell

[Leigh Hubner]

Boys!

 

It seems to happen when the unit should be at idle. My first guess was interference from handlheld radios but Im sure it happened once or twice while there was no radio chatter. I could be wrong but Im am pretty sure. I have tried changing freqs and on one set that did fix the problem. I couldn't make it jump once I changed but then walk onto another job and it was twitchy again. I guess I will have to try changing more often. I use a 2.4gig wireless Tx system, is this likely to cause issues? (I hope not as I love it!)

 

Jim, you say to isolate the motor cable. I don't quite understand. Are you saying that the actual cable my suffer from interference? Is there a particular type of motor cable that won't have this problem. I have several cables so that is a good one to try. Just never thought that a cable would be a problem. Interesting!

 

Thanks for the tips so far. If there are any more, feel free to keep them coming!

 

Leigh

[JimBartell]

Jim, you say to isolate the motor cable. I don't quite understand. Are you saying that the actual cable my suffer from interference? Is there a particular type of motor cable that won't have this problem. I have several cables so that is a good one to try. Just never thought that a cable would be a problem. Interesting!

Basically, the cable will act to some degree like an antenna and conduct RF into the circuitry of the receiver. In general you want to keep other cables away from the motor cable if you can. Different cables have different shielding so some may be better than others.

 

Jim "thinks RF is black magic" Bartell

[Steve Fracol SOC]

Leigh,

 

Jimbo just fixed one of my BFD's last month...was doing similar thing. Turned out to be a broken antenna that finally snapped. For the longest time I did not know it was broken because it was only partially broken where the threads go in. Once it finally snapped and Jim (master of his BFD domain) Bartell fixed it?.I had no more chatter issues.

 

Not saying that is your problem but you might remove your antenna and see if all the threads are OK, etc.

 

By the way JIM, THANKS FOR THE SUPER FAST SERVICE!!!

 

Good luck,

 

Steve Fracol, SOC

[David George Ellis]

Hey Guys,

 

It could also be an issue of updating the software in the RX. Real quick, easy and affordable. I had intermitent drop-outs on my BFD. No clue what was going on until I called Jim and gave him my serial #. He informed me there had been a few updates to clear up these hiccups and since then, not a problem. If you haven't already done so and have a "certified" pre-owned BFD, contact Mr. Bartell and see what you've got.

 

I did expeience a little "twitch" once during a job inside an insulated sound stage. Walkies, cellies, all sorts of RF bouncing all over the place. I literally opened the doors b/t takes and within two hours, the skies were clear again. Good luck

 

ONE,

 

David

 

P.S. Jim rocks, so sit on it