Shortly I got my AO-40 station operational. I am using a FT290 with DB6NT S-band downconvertor and a FT790 with homebrew PA (45W output). I also build a dedicated powersupply based on a burned-out Philips PS.
The antenna's are shown here. For 13cm downlink I use a 90cm prime-focus dish with a 2,5 turn helical feed. The downconvertor is mounted directly on the feed mounting plate. For the 70cm uplink a 2x19 elements F9FT crossyagi is used.
Currently I am building a downlink convertor for receiving the K-band downlink of Oscar 40 on 24.048 GHz. Here you see a testsetup dangling at my Polarad spectrum analysor which can handle signals up to 40GHz. I am using a DB6NT MK4 LO giving 50mW on 11952 MHz and a subharmonic mixer also from DB6NT. The WG-filter is experimental and not functioning very well: most of the tuningscrews have to be removed to reach the required passband. The preamp with a gain of 18dB and a NF of 2.5dB is shown here.
23cm datatransceiver
To make packetradio more 'fun' again I designed in 1998 this 23cm transceiver with which it is very simple to get QRV on 38.4 kbps up to about 150kbps. Running TCP/IP a lot is possible: browsing, mail, news but also streaming audio or even video! All you need is a transceiver, a modem and an scc-card in a pc running linux or jnos. Or a megabit tnc described next. The transceiver is operational at quite some nodes and users in the Netherlands and abroad. It can handle datatraffic using a manchestermodem but just as well WBFM audio. The NF is 3dB, and the outputpower is about 3W. Description/manual is available in english or dutch and also the software (3.0) for the Atmel 89C2051 processor. A description, schematics and pcb of the manchestermodem can be found here. When you click on the picture on the right you see some older photographs of the first prototype.
(Copyright (c) S53MV)
I build the megabit TNC as designed by Matjaz, S53MV. I used Protel for Windows to design and print the PCB. I use this TNC to communicate with PI1HVS, first on 38k4 but now on 1M2. In the photograph you recognise then tnc itself, to the right the scrambler modem for 1.2288 Mbps, in the upperleft corner the switching powersupply 12>5V and upright a max232 levelconvertor. On the PC-side, the TNC talks 115k2, or faster if your pc can (mine can't...). I prefer using SLIP, KISS in combination with TSTHWIN it did not work errorfree, probably because of the high speed at the PC COM-port. Furthermore, I consider the combination of KISS-programs on a Windows PC in combination with a TNC no as longer state of the art. The TNC is build using surplus components, I bought the 68HC000 years ago in Weinheim for 1 DM. Regretfully I only bought one...
The original software was adapted to accept Hayes commands for setting up the connection (ATDT etc) and a special command ATAX to set the various ax25 and IP parameters. Syntax: ATAX mycall-ssid, txdelay, txtail, persistance, kissmode, hardwareaddress of tcp/ip gateway. For example 'ATAX pe1jpd-0,40,4,128,0,pi1hvs-1'. This command is added in the modemsettings as 'extra initialization command' in Windows. Also the ARP-protocol is implemented.
Simplest AT89C2051 (ATMEL) Programmer
(Copyright (c) 1996 Silicon Studio Ltd.)
- schematic diagram
- zipfile containing schematics, executable and readme
High-speed node PI1HVS
PI1HVS has its own website now: http://www.pe1jpd.org:3737 (or http://go.to/pi1hvs sorry all in Dutch)
The node is a pentium 166, 64MB ram and a 1GB harddisk running Linux 2.2.14. User access is possible at speeds 4,800, 9,600, 38,400 and 1.288,000 bps. Services running are a node, a WWC, a http and ftp-server. The node in Hilversum is linked to PI1RNI in Utrecht (20kms) and to PI1HLM in Haarlem (40kms) on 1.2 Mbps on 13cm, the first high-speed interlinks in the Netherlands. Plan is to extend this network through the rest of the country. See for more inforamtion the webpages of PI1HVS.
The link to the internet is on 23cm/38k4, please keep this in mind when browsing the site..
You can reach the node at telnet://www.pe1jpd.org:3694.
OS-9: the ultimate operating system
Home made software for OS-9
OS-9 is a very interesting embedded multitasking operating system. It tasts like Unix/Linux but is much simpler and runs in rom if you like. Perfect for hobbyprojects.Pages are also available via packet-radio:
http://44.137.37.37 (PI1HVS)
Please send any comments, questions or suggestions to:
On the internet: [email protected]
via packet radio: [email protected]
