Gnd

Vp The positive supply bus Vdd The drain voltage supplied to the GaAs FET amplifier (don't forget any voltage drops from series resistors) Id The drain current Vbe The base-emitter drop (0.7 V, but temperature sensitive) (2) R1 R2*(Vbe + Vp-Vdd) (Vdd-Vbe) approximate equation I have had pretty good luck using equation 2 with R1 and R2 values in the low to mid kfi range. These equations seem to be close enough for picking standard values. The resistance values are assumed to be those marked on 5...

TCPIP Command Set Reference

By Ian Wade, G3NRW 7 Daubeney Close Harlirigton Dunstable Bedfordshire LU5 6NF United Kingdom I originally started using amateur TCP IP about 18 months ago, but found that the net package wasn't particularly exciting compared with the commercial versions I had been using elsewhere, so I didn't pursue it. Then, a few months ago, I decided to take another look at amateur TCP IP and discovered that Phil Karn and company had obviously spent some time sprucing it up. I decided I needed a...

New Packetradio Software Available

New packet-radio software has become available during the past month. The following information comes from CompuServe's HamNet and other sources. Although, all of the delineated software may be downloaded from HamNet, some of the software may be downloaded from other sources such as other on-line services, as well as, landline and packet-radio BBSs. ARES Data V1.5, file name ARES15.EXE, binary, 169752 bytes ARES Data is a multi-user, general purpose database program. Users connect to the...

Wj

2-way Coaxial Power Dividers (N-connectors) SPD2-144 432N 2m 70cm SPD2-220N 220 MHz 6 toot Coaxial (RG213) Jumper Cables 2 water cooling jackets with rubber gaskets for 7289 and 7815R tubes East Coast Amateur Radio, Inc. 496 McConkey Drive Tonawanda. New York 14150 (716) 835-8530 Complete line of Amateur Products available Specialty Products Division 85 Mary Street Aurora. Ontario L4G 3G9 CC-1 Capacitor Kit contains 365 pieces, 5 ea. ot every 10 value from 1pt to 33 f CR-1 Resistor Kit contains...

O

To build a single conversion receiver, with the objective of achieving exceptionally wide dynamic range. An example of this was G3PDM's classic phase-locked oscillator as used in his receiver 3 , This was a true synthesizer, albeit analogue, based primarily on valves, with a VFO using a FET and two bipolar transistors which is still regarded as the standard to beat. The author was present at a demonstration of this receiver where a signal below 1 microvolt suffered no apparent degradation from...

Space Station Packet Radio Operational

Musa Manarov, U2MIR, on board the Soviet space station Mir, received a packet-radio station by way of a cargo rocket that was launched on January 14 and had the station on the air by January 20. Musa operates in two packet-radio modes live keyboard-to-keyboard operation using call sign U2MIR-0 and mini-PBBS operation using call sign U2MIR-1. Virtually all of the packet-radio operations occur on 145.55 MHz. The U2MIR-1 PBBS commands are as follows B bye disconnects you from the PBBS J log...

References

Technical Topics' RadCom. December 1988 pp 957 - 958 2 Peter Hart COM IC-725 HF Transceiver' RadCom September 1989 pp 56 58 3 Peter Martin A receiver with noise immunity ana Frequency Synthesis', Radio Commum cation Handbook RSGB , fourth Edition pp 10 104 - 10.108, 4 Plessey Semiconductors 'Frequency Dividers And Synthesizers IC Handbook', especially pp 304 - 306. 5 Plessey Semiconductors Data Sheet SP8853 6 Plessey Semiconductors Data Sheet SP2002 7 JHJ Dawson Direct Digital...

QEX

The 1990 ARRL Handbook for the Radio Amateur, pg 12-8. By contrast, the brute force method works well for CW. It is easy to construct a Cohn filter from microprocessor crystals, and the NE602 mixer requires very few components. I hope that amateur experimenters will rectify the shortage of good information on using the phasing technique. I, for one, will be working on it, and offer Mr. Klingelhoeffer the challenge of presenting a simple, low-current design...