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ZL2APC, suggests that the vhf alignment aid described by J. R. Compton, G4COM. in the January 1976 issue of Radio Communication and see also alternative noise source by LA8AK in 7T, February 1978 is worthy of further publicity. He writes It is extremely useful, relatively simple and easy to get going. I modified mine of course what else to use a higher output noise source BC107 as a zener with a switched attenuator between the noise source and the output terminal lOdB per step ....

Voltagecontrolled noise generator

This idea comes from Jan Martin Noding, LA8AK G5BFV, although it is based on a suggestion by OB3RC in CQ-DL No 4, 1977. The circuit shown in Fig 7 has been modified to suit the particular requirements of LA8AK for use with the Alignment aid for vhf receivers described by J. R. Compton, G4COM, in Radio Communication, January 1976. Two units have been built and both worked instantly, delivering a maximum noise output of the order of lOdB nV . Several transistor types have been tried for TR2 and...

Miscellany

The January 1983 issue of QEX carried an article by Ivo Chladek, ZS6AXT, on the Microwave Alignment Probe. A number of individuals questioned the list of references given in that article. One letter summing up the situation follows The January 1983 issue of QEX contained a very neatly packaged Microwave Alignment Probe by ZS6AXT. In that note, the author referenced an article and comments contained in several issues of RSGB Radio Communication. These references ostensibly contain the heart of...

Using the SL SL nbfm ICs

John Wilson, G8KIS, and Richard Lambley, G8LAM, have been carrying out some practical tests using the new Plessey SL664, SL665 devices designed to provide i.f. af circuits for nbfm receivers and transceivers. Each of these devices provides the basis of a complete i.f. strip and consists of a preamplifier, limiting amplifier, quadrature detector, carrier squelch, dc volume control and audio output stage. The SL664 provides 250mW af output into 8fi, while the SL665 has low-level af output...