BrianS

That's too funny. I specifically had your kite in mind when I said I was going to keep my eyes open for a WM with a 3-point bridle It seemed like it could be about the same age as Rob's. It wouldn't surprise me a bit to learn that Devin did a retrofit somewhere along the line.

Yeah, that's definitely the way you want to go when you need to reduce pressure on the sail.

OK, that's interesting to hear. Since I've only ever flown a WM with the turbo bridle I don't have any basis for comparison. There are lots of folks around here with Widowmakers, so I'll keep my eyes open for a 3-pt bridle version and hopefully get a test flight. It sounds like the slack-line stuff is where you notice the most difference. Does it seem like precision and tracking are better with one or the other?

Thanks for posting the videos, Rob! I always enjoy watching you fly. I think that the turbo bridle is now standard-issue equipment on all Widowmakers. Both my Std. and UL came with turbo bridles and that's what's stated in the description on the Skyburner website. (The Kites and Fun Things website still says it's a 3-point bridle, but I'm guessing the description just hasn't been updated.) I'm really curious to hear about the differences in flight characteristics that you're noticing.

Thanks for the detailed test report, Terry. It's always nice to hear how these projects work out in the end. Congratulations to Ed -- it looks like your efforts were an unqualified success! Since you're using GMRS/FRS radios, it's unfortunately not possible to transmit stereo audio to the team members (at least not without making some major modifications to the radios). You could modify Ed's adaptor so that a team leader equipped with a stereo headset would be able to hear stereo, but the team members would still hear mono. The way it's wired now, Ed's setup sends the Left audio channel. If you feel like you're missing a lot of information from the Right audio channel, it wouldn't be terribly difficult to transmit a Left+Right mix into the radio's mono channel. In any case, there's going to be a built-in ceiling on the audio quality, due to the technical limitations of the GMRS format. Good to note. I would have made the same assumption. What is different? Is there a workaround? I run music off my smartphone. I actually use a set of earphones from an old iPod that probably doesn't work anymore. The earphones work just fine with my phone (and computer for that matter), so I would have assumed the connectors are the same. The iPod has a 3-contact connector: Left audio, Right audio and Ground. Many smartphones have a 4-contact connector: Left audio, Right audio, Microphone input and Ground. Unfortunately, there are (at least) two different standards for how the contacts to the 4-wire connectors are mapped to the different signals. Some smartphones are wired up in a way that's not compatible with 3-wire earphones. Since you already know that your phone works with a set of earphones, there's a good chance that one of Ed's gadgets would work for you out of the box. If not, you'd have to use an adaptor.

I'll add another recommendation for Ocean Beach when there's an onshore wind (which is usually the case). Lots of space and smooth winds. Crissy Field also has some nice open space for flying, but the wind can be pretty choppy.

That was a typo. Well, more than a typo...it was just drawn incorrectly. Thanks for catching the error. I edited my last post to correct the drawings. Let me know if you see anything else that looks wrong. Since you brought up the issue of the stereo plug to the music player, however, it is arguably better to use a stereo plug than a mono plug. When you connect the mono plug to the music player, the Left audio channel is connected to the tip. The Right audio channel, which would be connected to the ring on a stereo plug, simply gets shorted to the sleeve, which is connected to ground. In other words, you're shorting out the Right channel audio amplifier in the music player. I didn't mention this earlier, since you've already demonstrated that it doesn't cause a problem with your iPod. There's a small chance that you might run into a music player sometime that could be damaged by having its output shorted. I think it's a low risk, but if it makes you squeamish you could replace the mono plug with a stereo plug and just leave the Right channel output (on the ring connection) disconnected: Just to be clear, I'd put this last suggestion into the "optional refinements" category. The big feature upgrade would be adding the 4k resistor like you described in your last post. Edited on 5 August 2014 to remove a suggestion that was just a bad idea...

It seems like the potentiometer could be a nice feature to keep, since it allows you to adjust the relative volume of music and team leader voice that the team members hear. The volume control on the iPod is adjusted so that the music is at a comfortable volume for the team leader. With that particular iPod volume setting, the team members might find that the music is either too loud or too soft relative to the team leader's voice. The potentiometer allows you to adjust that mix until the team members are happy. The final adjustment is for each individual team member to adjust the volume control on their own radios until they're happy with the overall voice + music volume. The downsides are that this adds an additional adjustment that can get disturbed in the middle of a routine and the mechanical assembly is more complicated (you have to allow access to the mixing control). If it seems like the default 9.5k resistor gives you a good audio mix most of the time, there's probably no compelling reason to complicate life with the mixing control. If you decide to include the mix control, I have a suggestion for how you could optimize its behavior. The original circuit looks like this: One option would be to simply replace the 9.5k resistor with a 10k potentiometer, like this: This idea is not quite optimal, however. The adjustment range on the resistance is 0 to 10000 ohms. Assuming that the 9.5k is close to the value you want, your adjustment range ends up being 9500 +500 / - 9500 ohms or 9500 +5% / -100%. In other words, you can really only adjust the mix to make the music louder -- you have hardly any range left to make it quieter relative to the team leader's voice. Even if you did want to adjust the mix for louder music, you probably wouldn't ever want to go all the way to 0 ohms, so you wouldn't get much benefit from a large portion of your adjustment range. You may have already found a good workaround for those issues, but I'll offer the following suggestion for the benefit of anyone else that might want to make one of these. This configuration would allow you to adjust the mix for either louder music or softer music. You could put this together using components that you've already purchased. If you put two resistors in series, their values add together. In this circuit diagram, the new 4k resistor adds in series with the potentiometer's resistance. If you set the potentiometer to its mid-point, you get 5000 ohms from the potentiomter plus 4000 ohms from the fixed resistor, for a total of 9000 ohms. In other words, your adjustment range would be 9000 +5000 / -5000 ohms or 9000 +/- 55%. That gives you a really nice adjustment range that's almost ideally centered about the default 9.5k. It seems like that would work really well to cover just about any scenario. To do the setup, you'd set the potentiometer to mid-scale and the team leader would adjust the iPod volume control until the music volume is right in the leader's headset. Then do a field check with the music playing and the team leader talking. Adjust the potentiometer until the team members are happy with the voice-to-music ratio. There are lots of different ways to do it. This is just one suggestion. If it doesn't seem like you would need to adjust the mix very often, I'd be pretty tempted to go ahead with your plan to leave the potentiometer out of the cable. I'm a firm believer in keeping it simple whenever possible Edited 5 August 2014 to correct an error in the drawings.

Thanks for attaching the detailed test report. It sounds like you're really close to having this up and running and that you guys are on the right track with troubleshooting the remaining issues. I can't think of any reason that the wire bundle would cause a problem. Good luck and please keep us posted on your progress! -Brian

In this context is "static" referring to noise (e.g., random white noise) or distortion (i.e., bad-sounding stuff gets better/worse with higher or lower audio levels)? Is it correlated to movement of the setup/wiring, or is it there all the time? Those details would help a lot for tracking down the source of the problem. You'll be glad you made the switch to ceramic capacitors. There's a good chance DigiKey might stock the shielded cable you need -- they have a huge catalog. I've been ordering parts from them since I was 9 years old and they've never let me down. Great company.

Yeah, holding the push to talk button doesn't sound optimal Just to clarify, the primary concern with the polarized electrolytic capacitors is basic functionality and reliability, not the audio quality. If the circuit allows a reverse voltage across the capacitor it will eventually fail. If you absolutely must use them, I recommend that you verify that the in-circuit positive DC bias is always greater than the negative audio peaks to ensure that you don't ever subject them to a negative voltage.

Just a quick heads-up for you guys: I noticed from your photo of Radio Shack parts that you purchased polarized electrolytic capacitors for the mixing circuit. Since they're polarized, the direction you connect them in the circuit matters. Brett's schematic doesn't specify the orientation, so you might want to connect a voltmeter and check the DC voltage across the capacitor after you have everything hooked up and connected to the radio, headset and music player. If you're not in a hurry, you could mail order a ceramic capacitor from someplace like Digi-Key. Ceramic capacitors don't care about polarity and they'll have better linearity than an electrolytic capacitor (i.e., the ceramic caps would introduce less audio distortion...but it might be difficult to tell since the radio link isn't exactly high fidelity audio anyway). Here's one (of many) appropriate choices (47 cents each): http://www.digikey.com/product-detail/en/FK14X5R1E475K/445-8300-ND . Since it looks like you may be located in the Bay Area, another option if you are in a hurry would be to pick up a non-polarized electrolytic at Fry's ($1.39 each): http://www.frys.com/product/1710380 . Good luck with the project!

It does look like fun! The kite is an X-Masque VV from l'Atelier.

So...this means the dual-line clinic will be starting sometime around May 15? (Hey, you can't blame a guy for trying ) Best wishes for safe and happy travels. Keep me in mind -- it'd be great to see you while you're in the area. -Brian

Andy describes a "dynamic bridle," which I think is the same thing as a turbo bridle...so maybe there are only 9 different flavors you need to try

Andy Wardley has a very detailed description of bridle designs on his website. It's a great reference, complete with diagrams and detailed explanations if you follow the links for the different styles: http://wardley.org/kites/bridle/index.html

I'm glad to see that you already have the SF Bay Area on the map. You know, a clinic that had room for dual-line fliers might be popular around here...

I'm sure everyone's introduction to KiteLife is a little different. I confess that I visited as a guest for a few weeks before I signed up. If I hadn't had the opportunity to check out the archived forum posts and get a feel for the friendly and supportive atmosphere as a guest, I probably would not have joined. Once I recognized the value, I didn't hesitate to register.

I'm in!!!