It looks to me like a 1000uH (1mH) shielded power inductor. Digikey has about 14 PAGES of these, in various sizes and current/power ratings (the latter is likely to be important.) You can probably come close by picking one that looks the same and has the same size (measure it) (or just pick the highest power rating in that size.) For a better match, try to measure the DC resistance of your existing coil and match that as well.The eBay part looks like something entirely different.
I am trying to be preventative of issues. Ultimately the efficiency of range is what I am looking for, I want a clean noise floor both EMI and RF for the 100mw 433MHz data link to be able to both transmit and receive to the greatest distance possible, and for my 1.3GHz video link to get the best range possible without anything interfering with anything else. There will be a motor and servos running on the same battery too, as well as autopilot, OSD, GPS, Etc, so I think filtering will make all of the difference to get the best performance.I understand the concern, just question the method, or rather the lack of engineering methods being applied.That particular product in my OP according to it's specs are supposed to filter something from 1000MHz to 1400MHz noise, I guess the idea is to prevent noise from getting into the video TX, but I don't know enough about RF to know really if this circuit was good for the purpose or not.Not with caps that large, it simply can't be a bandpass or bandstop filter with corners at 1000 and 1400 Mhz. It is most likely a low pass Pi filter, but have no idea if it's still effective in it's stop band up to >1000Mhz. I am still waiting on some components to get in, plus I think I am going to order one of those USB SDR's (Capable of 50MHz to roughly 2.2MHz), which I could use as an RF meter to test RF noise, and I will see if my DSO Nano is capable of spotting any power noise on the power rails.Generally RF spectrum analyzers are the instrument of choice to look at and measure noise floor at any specific frequency(s) of interest.At this moment I am trying to really pre-plan everything as much as I can.One thing I know is that 433MHz has the ability to create harmonics close to 1.3GHz, and 1.3GHz can effect GPS, but luckily the airframe I am installing this onto is quite large so separation for RF components should be pretty good, but it also means longer wires and EMI to consider, toroids will be used on pretty much everything getting a power rail .Yea, that is a lot of stuff, and every installation tends to be unique when it comes to RF interference, EMI, etc.Good luckLefty