lml@lancaironline.net Mailing List Archive

In a message dated 5/17/2004 7:59:46 PM Central Daylight Time, jlbk@crestviewcable.com writes:

Just got back from CA (to central Oregon) and read the emails pertaining to
the ELT trip problem. On my last trip to Davis, CA when handed over to
Oakland Ctr from Seattle, (134.2) I think, I keyed the Xmitter of COM1 (SL
30) and the ELT tripped. Same thing the next day with NorCal aprch on
132.XXX. I only had about 50 hrs on my ES and this was probably the first
time I used a freg. above 130.XXX. The problem had not occurred before. I
later verified it only happens at the higher frequencies.
I talked to the tech people at ACK and they gave me the same story about the
Bob Archer antennas. I too am a EE but have no experience with RF stuff.
Still, I feel I'm getting the old "blame the other guy" story from ACK.
If anyone on the list can shed some light on this problem, it would be much
appreciated.
Leon

Leon,

I sent the following to Dan (private Communication) recently. What is your ELT mod level.

>>>>>>>>>>>>>

In a message dated 5/13/2004 7:41:08 PM Central Daylight Time, olsen25@comcast.net writes:

A little more about my setup.

COM1 (UPS SL30) connected to Bob Archer SA-008 antenna in the vertical tail
COM2 (UPS GX60 GPS/COM) connected to Bob Archer SA-006 antenna on right side of fuselage behind baggage area bulkhead.
ACK E-01 ELT mounted on left side of fuselage behind baggage bulkhead. ELT antenna is copper foil antenna with torroids as per Bob Nuckolls’ AeroElectric Connection. Antenna mounted on seatback bulkhead. ELT remote control in instrument panel and fed with the supplied telephone wire.
No antenna splitters anywhere – each radio has its own dedicated antenna
RG-400 coax everywhere

Dan,

Even if you have 2 antennas, when you transmit on one, the other should be disconnected from the unused radio. This may explain the loss of a radio, especially if com1 and 2 are set to the same frequency.

Antennas in proximity may certainly interact in supressing or resonating certain frequencies. Does your ELT fire only at certain com2 frequencies? Remember that early Garmin panel Mount GPS's requires a specific filter on the com antenna lines to supress harmonics of about 12 com frequencies (one of which was my airport's ground frequency), that disrupted the GPS operation.

The following is the letter I sent to ACK with my ELT:

<<<<<<<<<<<<<<<<

To: ACK Technologies Inc

424 West Julian Street

San Jose, CA 95110

408-287-8021

From: Scott Krueger

305 Oak Brook Road

Oak Brook, IL 60523

630-561-0400

Date: 4 April 2001

Re: RMF induced activation of ACK ELT Model E-01

Sirs:

I talked to Mike on 2 April about my problem with Garmin 430 radio transmissions triggering the ELT which is connected to an ELT exclusive use comm antenna about 6 feet from the transmitting antenna in a Lancair 320. He gave me some procedures to isolate the problem and also mentioned that ACK E-01’s were more resistant to this RMF induced activation if they were at the Mod 1 level. He also said if mine was not at that level, I should send it in to receive the free update. Therefore, I have enclosed the ELT for modification.

Thanks,

Scott Krueger

>>>>>>>>>>>>>>>>>>>>>

Good Luck!

Scott Krueger

Almost like I'm on VACATION.