passedoutwookie
Contributor
I have this issue also and it happens more or less continuously with at least one of my three transmitters. I’d be interested to hear what others have had success shielding the cable with.
OrcaTorch D630 and Perdix interference?
- Thread starter Thunder Struck
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
CPRC
Contributor
The hi/med/low question is interesting. I will put some focus on that next dive this week.
After a few back n fourths with Orca cust serv., I received the following response. Nicely broad. Whatever signal testing they performed didn’t work. Would be interesting to learn how they test. And I’m not sure what a “diving environment” has to do with it.
“Thank you for sharing your feedback with us. We sincerely apologize for the signal loss issue you mentioned regarding the Perdix computer. Our upgraded D630 product underwent signal testing before it was released, and we have received very little similar user feedback. We understand that signal issues may relate to your usage habits and diving environments, but testing cannot cover all scenarios, so we cannot completely guarantee that signal loss will not occur. We hope for your understanding.”
After a few back n fourths with Orca cust serv., I received the following response. Nicely broad. Whatever signal testing they performed didn’t work. Would be interesting to learn how they test. And I’m not sure what a “diving environment” has to do with it.
“Thank you for sharing your feedback with us. We sincerely apologize for the signal loss issue you mentioned regarding the Perdix computer. Our upgraded D630 product underwent signal testing before it was released, and we have received very little similar user feedback. We understand that signal issues may relate to your usage habits and diving environments, but testing cannot cover all scenarios, so we cannot completely guarantee that signal loss will not occur. We hope for your understanding.”
Wonder if a couple of clip-on ferrite beads/chokes would help here?
CPRC
Contributor
Please elaborate. When I think of “clip-on” I also think something dangly. But am unsure. The “wrap” idea mentioned early - I think tape-like, something that wraps along the beginning of the wire where it connects. I cannot imagine the entire wire needs wrapping. Hopefully someone that has experienced this same interference issue AND has tried a warp method will chime in here.
OP
In theory the chokes would have to be of the proper mix to mitigate the affect on the target frequency. The air transmitter is LF at 38 khz. So probably looking at something along the lines of a 76 mix? Never considered choking anything in that frequency. I don't think there's any ready made snap-on chokes commercially with a mix for LF.
The problem with the snap-on chokes is they are limited in the amount of suppression they provide, compared to having a wire wound and passing multiple times through a choke. The impedance of the choke goes up with the square of the number of times the wire passes back through the center. So getting a few wraps will do more than a whole string of beads. But then, you can run a whole string of them and loose some lead? Sure would make the wire unmanageable tho.
TLDR: Chokes need to be made from a material specific to the target frequency. Don't think you'll find a snap-on choke that goes that low in frequency, and if you did, you'd probably need a number of them.
The problem with the snap-on chokes is they are limited in the amount of suppression they provide, compared to having a wire wound and passing multiple times through a choke. The impedance of the choke goes up with the square of the number of times the wire passes back through the center. So getting a few wraps will do more than a whole string of beads. But then, you can run a whole string of them and loose some lead? Sure would make the wire unmanageable tho.
TLDR: Chokes need to be made from a material specific to the target frequency. Don't think you'll find a snap-on choke that goes that low in frequency, and if you did, you'd probably need a number of them.
lucca brassi
Contributor
If driver is in lid ( with high freq PWM) of canister only solution is shielded cable . Maybe ( new e/o ) cord WAM should do work better because of coaxial construction , but ground should be on coax mesh WAM E/O -Cord cable for battery tank, heater ... black
OP
So I dove my D630 and Perdix (2) yesterday to see about reproducing the interference problem. I had the Perdix on my left wrist/forearm area, Swift transmitter on right side HP port on a 6" Miflex hose, D630 canister on lower tank cam band on the left side cord oriented up, with the cord around my left side, across the chest with the light head on my right hand. With this configuration I saw no interference issues with the Perdix and the Swift. If I placed the light's cord across the Perdix then it would quickly lose signal. But given the configuration of how I had it setup, it didn't come close enough to the Perdix to cause problems, I had to place and hold the cord in that position to get it to lose connection.
Next time I'll try mounting the canister on the upper cam band on the right side near the Swift and see how that fares.
While this was diving in freshwater, saltwater has greater electromagnetic attenuation so results could be different, however, I used this same configuration before in saltwater and hadn't noticed problems. This placement is also not what in recommended by Shearwater which is the computer and the transmitter should be worn on the same side.
If it were possible to see the signal strength recieved from the Swift on the @Shearwater Perdix, it could help troubleshoot equipment placement.
My test was in freshwater. Saltwater should attenuate any electromagnetic signals such that the interfering RF noise from the light cable would be reduced. But this also means the signal from the Swift would also be attenuated, and given the distance, I'm thinking the Swift is attenuated more so than that of the EMI from the light cord as attenuation is a logrithmic scale.
I've got plenty of vacation time if someone wants to put me up for a few weeks in the Caribbean for a series of controlled tests, I'm game. Coastal Califonria or Catalina would work too--have drysuit, will travel.
Next time I'll try mounting the canister on the upper cam band on the right side near the Swift and see how that fares.
While this was diving in freshwater, saltwater has greater electromagnetic attenuation so results could be different, however, I used this same configuration before in saltwater and hadn't noticed problems. This placement is also not what in recommended by Shearwater which is the computer and the transmitter should be worn on the same side.
If it were possible to see the signal strength recieved from the Swift on the @Shearwater Perdix, it could help troubleshoot equipment placement.
My test was in freshwater. Saltwater should attenuate any electromagnetic signals such that the interfering RF noise from the light cable would be reduced. But this also means the signal from the Swift would also be attenuated, and given the distance, I'm thinking the Swift is attenuated more so than that of the EMI from the light cord as attenuation is a logrithmic scale.
I've got plenty of vacation time if someone wants to put me up for a few weeks in the Caribbean for a series of controlled tests, I'm game. Coastal Califonria or Catalina would work too--have drysuit, will travel.
Similar threads
