I have an aero. search and rescue beacon transceiver from a Govt.
surplus store.
When I connect the homemade(bike spoke) ant. to the casing(at the same

time it is connected to the proper ant.input site) it changes to
receiving a different air to ground conversation,than if I don't
connect it to the casing.I presume it must be changing the frequency of

transmission received.
Why/how does this occur?.
Thanks.

Hi,

If it is a UK SARBE unit made by Burndept, it probably uses a
super-regenrative receiver (i.e. self-oscillating detector) hence
the tendency to pull in frequency. They were designed as a
'downed-airman' distress beacon on 121.5 or 243MHz (usually with
a secondary non-distress channel), where the receive
specification doesn't need to be particularly high and with a low
battery consumption figure.

Horrible things, although I guess they will have saved a good
few lives in their time.


Cheers - Joe

Thanks alot for the explaination,Joe.
Yes, it is made by Burndept Co.,'S.A.R.Be.,with voice'.
Therefore its a transceiver,with distress bleeper.
When its on receive without earthing the ant. to the body it
interferes with BBC1 reception.
It was yellow, but has been poorly painted in camo. colours, prob. by
Army.
It has what looks like a small lead acid battery connected, but I cant
get it to charge or work. I use a 9v d.c. supply to work it.
Thanks, Hartly.



Joe McElvenney wrote:
Hi,

If it is a UK SARBE unit made by Burndept, it probably uses a
super-regenrative receiver (i.e. self-oscillating detector) hence
the tendency to pull in frequency. They were designed as a
'downed-airman' distress beacon on 121.5 or 243MHz (usually with
a secondary non-distress channel), where the receive
specification doesn't need to be particularly high and with a low
battery consumption figure.

Horrible things, although I guess they will have saved a good
few lives in their time.


Cheers - Joe

Hartly,

It has what looks like a small lead acid battery connected, but I cant
get it to charge or work. I use a 9v d.c. supply to work it.
Thanks, Hartly.

Years ago, one of the departments under me used to repair SABRE's.
There is an official battery adaptor but they used to take the guts out
of an unserviceable battery, drill a hole in the fluted end and feed
wires into it. I cannot remember the battery type as it was some years
ago but I don't think that it was ordinary carbon zinc, alkaline or even
NiCad/NiMH.

The idea as I remember it was for there to be a beacon (alternating
tones) on the distress channel and an airman to rescue craft talk-back
channel for when they got close to him/her. We used them on different
frequencies though for ground to helicopter liaison which was not very
mission critical. You could easily heave it and try another one if need
be. I once pulled the ring on one of the older models when in a mate's
car and it nearly put his eye out when the antenna suddenly unfurled :-(


Cheers - Joe

Hello Joe,
Yes, I forgot to mention I've removed the nasty sharp rolled steel
tape ant.and replaced it with a bike spoke.
I'm thinking of using 50ft. of wire to extend the ant. down the garden
from my window to see if I can receive the ground end of the
conversations.

Hartly.

Joe McElvenney wrote:
Hartly,

It has what looks like a small lead acid battery connected, but I cant
get it to charge or work. I use a 9v d.c. supply to work it.
Thanks, Hartly.

Years ago, one of the departments under me used to repair SABRE's.
There is an official battery adaptor but they used to take the guts out
of an unserviceable battery, drill a hole in the fluted end and feed
wires into it. I cannot remember the battery type as it was some years
ago but I don't think that it was ordinary carbon zinc, alkaline or even
NiCad/NiMH.

The idea as I remember it was for there to be a beacon (alternating
tones) on the distress channel and an airman to rescue craft talk-back
channel for when they got close to him/her. We used them on different
frequencies though for ground to helicopter liaison which was not very
mission critical. You could easily heave it and try another one if need
be. I once pulled the ring on one of the older models when in a mate's
car and it nearly put his eye out when the antenna suddenly unfurled :-(


Cheers - Joe