Project #1: Remote (HF-)station control via a VHF/UHF-link
After having been in my cold, windy and humid dx-shack for many (but not nearly
enough) hours, the idea arose for project #1: remote (HF-)station control via a
VHF/UHF-link.
I like the idea of having the tremendous good reception of DX that comes with the
usage of my far-away beverage antenna's,
combined with the comfort of controlling this station from my "lazy Boy"
at home in Opmeer. And, making this DX-station accessible over the air, will also
make it possible for other people living within VHF-range of Opmeer to make use of it.
The idea is to install the HF-rig and PA
together with a modest computer for control-purposes somewhere on a farmer's
premises where I have access to the 220Volt mains.
Two VHF-links, one for the transport of
audio to and from the remote HF-rig, and one for remote control of the
HF-rig via packet should then do the trick ......
Of course, special precautions will be taken to assure only authorized visitors
will be able to use this dx-station. These precautions will be made thru the use
of cryptographic techniques and more specific thru the use of certificates.
What does this mean?
Assume PA0AAA is a full-licensed ham who wants to operate my DX-station.
To be able to do so, he needs the following things:
- The Windows-95 based radio-control software to be installed on his PC
- A 1200 Baud packet radio-modem
- Two (2) VHF rigs (with decent antenna's!)
- A certificate, issued by PA3FUN (That's me!)
In time, the radio-control software can be downloaded from this page without any
restriction.
The certificate is different "cook".
What is a certificate anyway?!
A certificate is a set of bits that is used as the digital signature of PA0AAA.
A digital signature is used in securing the communication between computers in much
the same way as a traditional handwritten signature is used to secure the written
communication between persons.
In the concept of my DX-station the certificate is used to digitally "sign" all control
commands that
PA0AAA sends over the packet control-link. Digitally signing every control
packet means that the computer at the DX-station can verify
with absolute certainty that every command received really was originated at PA0AAA's station.
There is no way any other station, that does not hold possession of PA0AAA's certificate,
can pretend to my DX-station he (or she..) is PA0AAA. No way!
In order to obtain a certificate,
PA0AAA has to fill in a form with some personal data that can persuade me that the person
applying for the certificate is with no doubt PA0AAA.
Heavy, don't You think?
Would You like to obtain a certificate, and do You live within a 50 km range of my
DX-station's QTH? If so, drop me a line via E-mail! Or better yet, sign-up the
mailing-list on my homepage!