Mountain Avid finally Flys

[NorthIdahoAvidflyer 374]

John M. I have a 20,000 MFD capacitor on the way. The other day while flying, one of the local instructors told me that all he could hear was a "click" when I tried to transmit. I finally figures out that it was the battery pack I have been using. It's one of the type that you add alkaline batteries to. Once the batteries get so low they don't have enough deep cycle capability to maintain a transmission.

I have one of the battery packs that has a cord running to a cigarette lighter plug. Ir works great to power the radio but they I have to put up with the whining from the engine. 

I will take some pictures of my ground and and power buss and post them tonight. I have my 12 volt auxiliary/cigarette plug port connected right to the battery and use them to power my intercom and radio. maybe you or Chris could give me an idea on where to install this noise filter.

 

It sucks but the power supply Icom sells will likely fix your issue. https://www.sportys.com/pilotshop/cigarette-lighter-adapter-for-icom-a24-a6-transceivers.html?utm_source=google_shopping&m=simple&mrkgcl=596&mrkgadid=3208669406&utm_medium=cpc&utm_campaign=Avionics+%26+Radios&adpos=1o2&creative=295428070003&device=c&matchtype=&network=g&gclid=EAIaIQobChMIhuH8gZbG3QIVAb7ACh3hxQLaEAQYAiABEgJkX_D_BwE

Joey and I have talked about this before and the reason I did not go with his option was because someone had asked if the radio could be operated while plugged into the CP-20 Charging cord. Here is the Q&A from the Aircraft Spruce website. 

Yet this is what the ICOM website says:

This is the kind of shit that drives me crazy........ 

 

 

 

[akflyer 1427]

don't put to much faith into the descriptions on the spruce site... go with whats on the manufactures site.

[NorthIdahoAvidflyer 374]

I got the GSC propeller reset day before yesterday and took her up yesterday evening to check RPM. Its running 6750 RPM straight and level WOT. Climb power is so much better with more RPM. I am still waiting for bolts for the new Ultra-prop. I hope it pulls as good as this GSC. 

I got this Face Book message from a guy on the field. It's amazing how many people stop by and comment on the Mountain Avid. They love that thing!!!

 

 

 

 

[NorthIdahoAvidflyer 374]

Back to the redio noise issue:  I found out the radio battery pack (one that takes the AA batteries) was my best option for less noise but the batteries don’t last long using it for transmitting. When they discharge to a certain point they cut out your transmission completely. 

 I really like the battery pack that plugs directly into a 12 volt cigarette style outlet but it feeds a lot of extra noise into the system. As mentioned here and from what I could read on the internet a simple noise suppressor works very well for filtering out inline noise coming through the power source. I purchased one and it arrived today.

I have all of my instrument panel ran off a main buss and ground buss which is located behind the panel. When I installed my dual plug adapter I pulled the feed wire directly off of the battery because it was close to where I wanted to mount it (face of the seat truss under the passenger side) and I didn’t have to pull another wire across the floor.   I think the easiest way to install this is to pull the seat and wire it inline to the existing 12 volt power source. This should kill most of the ignition noise to the intercom and radio as they both are powerd from the same source.

The system is sending and receiving well. I can hear traffic a long ways away and they seem to hear me ok. If this little gadget can clear a lot of the ignition whine out of the intercom and radio I’ll be in good shape. 

I will report back once I install the noise suppressor. 

[nlappos 413]

I had so much engine ignition noise no radio would work, here is what I did that worked well, explained in this thread:   http://www.avidfoxflyers.com/index.php?/topic/3636-noisy-radio-emi-fix/

[Guest]

Hi Vance,

Have you determined if the noise in the radio is conducted (through the charging port) or radiated (coming in through the antenna)?

I think I lost track of where you are in the process of sorting this out. If the noise is radiated, Bosch metal shielded resistor plug caps are far and away the best solution. If the noise is conducted, a properly placed big ass capacitor (like the one you are talking about above) might solve the problem depending on a lot of variables in your wiring. A better solution (or in addition to the big ass capacitor which may or may not work) is to use a three wire filter like the one in one of the photos above in this thread in series with the radio power lead.

Curious, if you look at the radio where the charger plugs in it should state the required voltage. What is that voltage?

Chris

[NorthIdahoAvidflyer 374]

Chris, When I ran the battery pack with the AA batteries the RF noise was cut way down. Mind you I was still running the Intercom off of the 12 volt source so I believe there was still some noise being generated through the intercom via the power source. This noise eliminator if nothing else will help me answer the question if the noise is coming through the power source or radiating from somewhere else. At very high RPM settings there is a radiant noise that I believe is feedback between the intercom and the radio, I may be wrong on this and it may be that the shielded caps may be necessary to cure that issue. 

This sure has brought up some great conversation and I appreciate all the feedback. 

[Guest]

Hi Vance,

Didn't realize you had an intercom too. When you hook up that filter be sure both the intercom and radio receive power from the filter and not just one or the other.

That is unless you are running the charging lead out of the rectifier through the filter before it hits the battery and buss. That might work and the benefit would be all DC in the plane would be filtered, and you would be filtering at the source which had additional advantages. The only two concerns I would have with this approach are 1) is the current rating of the filter adequate to handle the alternator output? 2) What is the voltage drop of the filter? Will it limit the ability of the alternator to properly charge the battery?

Chris

[akflyer 1427]

My brother KF had bad noise in it when I used the 12v power to run it.  I put a filter inline from NAPA straight off the rectifier / regulator to the battery to filter everything.  That was 8 0r more years ago and its still going strong and no radio noise anymore.  We are running the metal caps on it as well.

[NorthIdahoAvidflyer 374]

Chris, Here is a picture of the details listed on the side of the Filter.  

Another question?? Right now I am pulling power for the 12 volt power source directly off both polls of the battery. Would there be any benefit to grounding the ground lead off of the plane body verses the batteries negative poll? I plan to ground the filters ground wire to the planes body.

 

[chopndrag 226]

I moved my radio lower to the floorboard and now I get the high pitched noise at full power. When it was mounted on my dash everyone could hear me fine. I'm also running rechargeable batteries in my set up and the simple rubber duckie. At some point I need to get a new radio antenna and elt antennna but for now it's doing the job . On take off is when the guys notice my engine noise . At cruise it's ok so who knows. 

[Guest]

The more I thought about it the more I liked the idea of placing that filter in line with the rectifier/regulator and filtering the noise out at the source. But I looked up the magneto/alternator output capacity and it is 170 Watts. That translates into about 14 amps at 12 volts. Unfortunately the filter in the picture is only good for 12 amps peak and 10 continuous so you’d be taking a chance on it burning up. 

As far as hooking the filter up, I would prolly bag the radio specific wires going all the way back to the battery even tho the cleanest power will be there. I would hook the input wire of the filter to the output of your radio/avionics switch or straight to the power buss if you use the switch on the radio and intercom to turn them on and off. I would ground the filter at one of the top center engine mount/firewall bolts to ensure a good airframe ground and run the output wire to the intercom and radio power input connections. 

Then I would get 4 Bosch metal shielded resistor plug caps, install them, and ur noise will be gone as if by magic!

[NorthIdahoAvidflyer 374]

Chris, Just so I have this straight..... You would do away with the wire I'm running directly from the battery to the radio/intercom power source. I do not have a radio/avionics switch but what I'm hearing you say is that I should run the filter off of the power buss behind the panel so that when I turn the Master off all power to the radio/intercom is cut off and there would be no chance of me accidently leaving the radio/intercom on and draining the battery when I'm done with a flight. Am I understanding you correctly?

I looked for the Bosch metal caps and cant seem to find ones made from Bosch but I did find a lot of aftermarket ones on ebay. Do you know of a specific outlet for Bosch? Are these other metal caps going to do the same thing?

 

 

[Guest]

Hey Vance nice talking to you yesterday. I will be home this evening and we can talk again. 

As for the questions above I believe that with the filter you do not need to attach at the battery. There are a couple of benefits. 1) like you said radio and intercom will be on master so battery will not be drained if u accidentally leave them on. 2) I believe the number of wires connected directly to the battery should be kept to a bare minimum because each wire is its own possible source of combustion should insulation wear through and ground out. The purpose of the master switch is to completely disconnect the battery should something accidentally short out. Each random connection to the battery that isn’t switched via the master is another source of combustion that has no emergency  discount.

i will try and find a source for the Bosch shielded resistor plug caps.

Edited 30 Sep 2018 by Chris Bolkan

[NorthIdahoAvidflyer 374]

The wind kicked up this weekend so I got a few projects done. I installed the new prop bolts, added the new jet needles, and installed the noise filter. 

The jet needles didn’t do much as far as cooling the upper midrange. Still running near 1200 in cruise.

I ended up wiring in the noise filter at the battery because it was the easiest place to put it for a test.  It made a lot of difference. I would say it cut out 90% of the high pitch noise I was getting at high rpm. This proves there was a lot of noise being transmitted through the radio/intercom power source. It’s almost quite. I think I will move it to the main power buss so it shuts off with the master. Right now I’m pretty happy but will work to cut out even more noise.  Next will be shielded spark plug caps.

 

[Guest]

Hi Vance,

If you are going to leave it that way for long I recommend putting an in-line fuse between the battery and the filter. Right now there is always power going to the filter, and the filter has at least one capacitor in it. Should that capacitor or anything downstream of the filter fail in a short circuit, there is no over current protection. That could lead to a very bad situation should it fail and short out in flight. At the very least lots of smoke, at the worst fire. An in-line fuse on the red wire right at the battery will make it safe.

Chris

[NorthIdahoAvidflyer 374]

Hi Vance,

If you are going to leave it that way for long I recommend putting an in-line fuse between the battery and the filter. Right now there is always power going to the filter, and the filter has at least one capacitor in it. Should that capacitor or anything downstream of the filter fail in a short circuit, there is no over current protection. That could lead to a very bad situation should it fail and short out in flight. At the very least lots of smoke, at the worst fire. An in-line fuse on the red wire right at the battery will make it safe.

Chris

Good call Chris. I actually have an inline fuse but its on the other side between the filter and the power source.

That is another good reason to install the filter at the panel......You are not powering the filter all the time when not in use. I never considered that. 

As far as the shielded caps......They are listed by the size of the thread on the spark plug. The plugs we use are solid top. If you go to the non-solid top BR8ES they have a 14mm thread. Do these shielded caps screw onto to the plug?  I could only find one shielded cap on Ebay for 14mm. There are a tom of them for 10 and 12mm. I emailed the place that had the 14mm shielded cap and they literally only have one cap. :(..

  

[Guest]

Hi Vance,

Edit: The Shielded plug caps Snap onto the plugs, they do not screw on. They are actually secured by spring force at the base of the plug on the hex. I still safety wired them on in addition to their snap on force.

It's been years since I used the Bosch shielded caps. However, if the shielded caps will work with a screw off br8es plug that's perfectly OK because the cap would be unscrewed and not used with the shielded plug cap. Otherwise the solid top plugs would work. Make sense?  You would just switch to standard BR8es plugs. Wish I could remember, but I can't. That bit of info is gone forever from my mind. :-)

Chris

Edited 1 Oct 2018 by Chris Bolkan

[NorthIdahoAvidflyer 374]

I was just wondering if you had to use the plugs capless. If I can not find one in 14mm I was hoping to buy a set for 12mm and use them with a solid cap plug. Does that make sense?

[Guest]

I am having a dickens of a time finding the Bosch caps I am talking about, but I found an image.

This might be one source: https://www.gsparkplug.com/1x-bosch-sheathed-spark-plug-cap-1k-0356351031.html

Edited 1 Oct 2018 by Chris Bolkan

[NorthIdahoAvidflyer 374]

Apparently they do not produce them anymore. I found these. I purchased them. Hope they work. 

 

[NorthIdahoAvidflyer 374]

I got the new caps and they do not work with the solid cap BR8ES plugs. They work with the standard screw off cap style after removing the cap. It grabs the threads of the plug. I will have to trade my plugs in for a set of the screw top style which shouldn’t be a big deal because they are easier to find anyways. 

Im hoping these metal caps work to get rid of more radio noise. So far every little thing I’ve done has helped eliminate a little more.

 

 

[flywise 169]

Hey , I am just wondering what impedance is best with the 912. Some caps are 1kΩ and the ones you bought are 5 kΩ....

I found this company selling caps for the 912 and they're 1 kΩ....

https://shop.brp-rotax.fr/en/all-rotax/12667-983409-shielded-spark-plug-connector-bosch.html

 

[NorthIdahoAvidflyer 374]

Here are a few pictures of the new shielded caps. I did have to change back to the screw top plugs but it was no big deal. They are actually easier to find locally. 

I have been worried about the EGT’s. The plug test shows good brown color. 

After talking with a few people who are much smarter than me about installing ignition noise filters I removed the one I installed and ordered a bigger one. The new one will be installed between the regulator and the main power buss. My 12 volt cigarette style power supplies will now run off of the main power buss instead of directly off of the battery. Once installed the new system will filter the whole power system right at the source and will shut down the power supply with the master switch. This should keep me from inadvertently killing my battery because I forgot to turn the radio or intercom off.

 

[FredStork 453]

It is a good idea to secure the caps like you have done.  Here is a way to do it that makes it very easy to take them on and off when so needed (like I had to do before each flight until I found the "P" plugs...)