Translation came from Berni, DL6XB. Thank you.

Project 10m-FM-repeater HB9HD    
General information

The 10m-FM-repeater HB9HD is a true ambitious thing. At this time it is
licenced. Probable it would be the only repeater in this area of switzerland;
because in region 1 we have not more than 4 frequencies in 10 kHz interval.
They are all in use in europe and cannot be used as often as we want because
with good conditiones the interference would be so strong that the normal
traffic wouldn't be possible any longer.
And because of the extremly small 100 kHz-duplexdifference the same QTH for RX
and TX cannot be realized without undefendable expense. In consequence of the
full-duplex-use the problem is the separation of TX- and RX-frequency: Not only
the price of the necessary filters, but the mechanical dimensions would be out
of place. Therefore you need two different places for RX and TX connected
through a link. All other repeaters of this sort are working in this way.
Selecting the places we didn't take it easy. We looked for two high QTH's in
direct sight-communication. As for the HF-technics they should be comparable
so, that near-by user will find the same conditiones for both the RX- and the
TX-way. And: The repeater should have a big range for in bad conditiones it
should be interesting too. Another point: You should be able to reach both
places by normal transport the whole year through. You need a building, alter-
nating current, a room without public traffic, and - of course - an antenna on
the building!
In the end all this we found in the central switzerland: We will build up the
TX on the Fronalpstock 1905 m obove sea level, the RX 240 m deeper on the Rigi.
The distance between those two mountains is ideal with 11 km. The separation is
o.k. and it's not too far for a link on SHF.
With intent to build up later some more receivers we deceided to put the TX on
the highest point so that through an auto-diversity-equipment the best received
signal can be transmitted. In this way mobil-stations as good as dx-stations
will achieve good results. But at first HB9HD will work with only one receiver.
From this places we exspect the repeater will work to central-, northwest-,
north-, and northeast Switzerland including greater parts of the countries near
by from Elsass up to Munich.
HB9HD developed the intelligent controls for the repeater and likewise the con-
trols of the uhf-repeater in Kyburg and since autumn 1995 the Piz-Corvatsch-
repeater in Engadin.
The controls are working on microprocessors and are able to get all optiones
you need, for example (through DTMF, ZVEI etc.):
- ask for a rapport, answer in CW ore voice
- ask for batterie-voltage
- ask for temperature of power-amp.
- ask for weather broadcast etc.
- the repeater can work as a beacon or without sporadic-e-warning
- you can open the squelch
- you can stop transmitting
- some of the controls you can do via packet radio
In the future we will have links to other repeaters on VHF ore UHF.
And because on the Fronalpstock the UHF-repeater HB9CF works a link to this
repeater could be easy to install. Another UHF-repeater is the one in Kyburg,
where the technical equipment is ready to go.

HB9HD, Highfrequency Digitalgroup Oberneunforn, June 1996