Becker speaker/microphone box - shall i get rid of it?

[Domenico Bosco]

My glider is equipped with a quite old Becker box. The microphone cable is in very bad conditions and i have a bunch of cables going back and forth from the panel to the box, which is fixed close to my right shoulder behind the seat. I'm wondering if this is really necessary, or if i should go for a much cleaner setup with just the microphone cables and the ptt cables starting from the radio and that's it. Is there any good reason to keep the Becker box, and refurbish all the connection cables?
Thanks for any advice.

[Martin Gregorie[_6_]]

On Sat, 02 Jan 2021 05:10:42 -0800, Domenico Bosco wrote:

> My glider is equipped with a quite old Becker box. The microphone cable
> is in very bad conditions and i have a bunch of cables going back and
> forth from the panel to the box, which is fixed close to my right
> shoulder behind the seat. I'm wondering if this is really necessary, or
> if i should go for a much cleaner setup with just the microphone cables
> and the ptt cables starting from the radio and that's it. Is there any
> good reason to keep the Becker box, and refurbish all the connection
> cables?
> Thanks for any advice.

I have a KRT2 in my (removable) panel: I fly a Libelle, which has nice,
slide-out panel.

The KRT2 routes all connections through a single D15, so I ran the PTT
wires out to a socket in the panel baseplate - this connects to the PTT
switch on the stick with a screw-on two-pin plug. Similarly, a length of
dual coax leaves the panel via a 4 wire screw-on connector inside its
rear right corner and terminates in a junction box on the cockpit wall
containing the speaker and with a gooseneck mic mounted on it. Does what
I want: the wiring is quite tidy and, most important, is easy to connect
and disconnect when the panel is brought home for the winter.

IME time spent tidying up the wiring and arranging it so that both the
wiring harness and the instruments connected to it can be removed and
refitted without cutting or (un)soldering anything is never time wasted.
XLR connectors [1] work well for battery connections and circular multi-
pin connectors with screw-on retaining collars work well for just about
everything else.

I never run connections directly between interconnected instruments:
instead I fit a D-series plug to the end of each cable. I have a metal
box, with matching LABELLED D-series sockets mounted on holes cut in its
lid, one for each instrument connecting cable. Inside the box, the
interconnection are made by soldering colour-coded wiring between the D-
series sockets on the inside of the box lid. Wire colours are consistent
and meaningful: black=ground, red=+12v, green=GPS data,...

This makes the wiring neat, near-impossible to damage and self-
documenting, so any rewiring thats needed if/when you replace an
instrument becomes very easy to do.

[1] the XLR connector that connects both batteries to my panel has a
right-angle cable entry. It and didn't like being kicked or knocked,
which caused momentary disconnects, but when I soldered a 5 ohm wire
wound resistor in series with a 1000uF electrolytic capacitor across each
pair of battery leads that problem vanished: the electrolytic can source
up to 5 amps briefly (safety measure and reduces the surge on connecting
the battery) and the capacitor holds enough charge to power the
instruments through the momentary disconnection if I knock the
connector.


--
--
Martin | martin at
Gregorie | gregorie dot org

[John DeRosa OHM Ω http://aviation.derosaweb.net]

On Saturday, January 2, 2021 at 7:10:44 AM UTC-6, wrote:
> My glider is equipped with a quite old Becker box. The microphone cable is in very bad conditions and i have a bunch of cables going back and forth from the panel to the box, which is fixed close to my right shoulder behind the seat. I'm wondering if this is really necessary, or if i should go for a much cleaner setup with just the microphone cables and the ptt cables starting from the radio and that's it. Is there any good reason to keep the Becker box, and refurbish all the connection cables?
> Thanks for any advice.

Domenic,

I have only seen a Becker (or Dittel) speaker/microphone box installed in one glider. The idea of the box is to simplify the installation of a radio. This starts with a pre-made wiring harnesses and a microphone with a DIN connector. Then add a speaker box and it is kind of "plug and play" - albeit by adding additional cost to the bottom line.

You can eliminate the speaker box by connecting power, speaker, and PTT directly to the radio's DB connector. That part is not particularly difficult.. However, attaching the microphone's very thin wires (26ga or less), plus multi-stranded shielding, to the DB can be a bit trickier. There are some hints on this at http://aviation.derosaweb.net/presentations/#wiring (slide 63-65) and http://aviation.derosaweb.net/presentations/#transceiver.

Personally, I prefer making my own radio harnesses. They are always just the right length.

My $0.02.

- John (OHM)

[Domenico Bosco]

Thanks John! I think i will remove the box, and i agree with your comments! Luckily, i already have all the welding done on a spare db connector coming from my older glider (full compatibility, same glider, same radio). I just want to add that i need to thank you a lot, i have all your presentations, and i use them continually during those days. I'm re-building completely the instrument panel, and those presentations are fantastic, lot of good hints! Thanks again and i'm looking forward to see more updates on your page!
Best regards,
Domenico