Need help with inexpensive wired lavalier mics for Xenyx 802
I'm a psychotherapist, and I record most of my sessions on DVDs. I sometimes show sessions (with patient's permission, of course) when I teach other therapists. The sound needs to be reasonably good, but needn't be professional quality. Until recently I was using two Samson QL5 Concertline lavalier mics. Each has a mini-XLR plug that goes into a "PM6" adapter, which then connects by a full-size XLR cable to my Xenyx 802 mixer board. This worked well until one of the mics broke. They have been discontinued without a successor, as the world seems to be going wireless. I've avoided wireless because I want a set-up that I don't need to be testing and checking: I want to be able to put the mic on and be confident that it will work.
I have tried a few replacement mics with mini-XLR connectors but have discovered that they don't work well with the PM6 adapter unit: there is hum, level is too low, etc.
I finally gave up on the mini-XLR mics and got an Olympus ME-15 for $20, which has a 3.5 mm mono connector. Frankly the sound seems perfectly adequate, but it doesn't work at all when I plug it into the Xenyx unit with a 3.5 mm to 1/4" phono plug adapter, presumably because it needs a 5-10v bias voltage that the Xenyx is not supplying. When I run it through one of the video cameras it works well. But when I do that, I can't run the mic through the mixer board. The other problem is that it works fine for my mic, which is near the mixer, but the patient mic gets a huge amount of hum when I run it through a 25 foot 3.5 mm cable, even though the cable claims to be shielded.
So my questions:
1. Is there a simple, preferably inexpensive way to provide the bias voltage for a mic with a 3.5 mm connector and run it into the Xenyx board? I'm assuming it would have to be a 3.5 mm to XLR adapter with a power supply to convert the phantom power into the right voltage range. I'm assuming that converting it to XLR would solve the shielding problems for the mic that needs the 25 foot cable.
2. If not, is there another solution for a wired lavalier mic that I can run to the Xenyx board? I need lavalier mics because the alternatives seem to pick up too much ambient noise such as heating systems. I keep saying "inexpensive" because (a) the mics are prone to break, especially the clips as patients handle them, and (b) I also recommend the set-up to other therapists. I tried the Audio-Technica ATR-35s, but (a) the shielding was not adequate so I got a lot of 60-cycle hum, and (b) the battery will run out at some point and I won't realize it, because, as with the wireless system, I don't have a sound person running a check every day or before every session.