Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site brl-tgr.ARPA
Path: utzoo!watmath!clyde!burl!ulysses!mhuxj!houxm!vax135!cornell!uw-beaver!tektronix!hplabs!hao!seismo!brl-tgr!jcp
From: jcp@brl-tgr.UUCP
Newsgroups: net.ham-radio
Subject: Re: some questions about UNIDEN CR2021
Message-ID: <4806@brl-tgr.ARPA>
Date: Fri, 28-Sep-84 00:36:51 EDT
Article-I.D.: brl-tgr.4806
Posted: Fri Sep 28 00:36:51 1984
Date-Received: Wed, 26-Sep-84 06:31:17 EDT
References: <12141@sri-arpa.UUCP>
Organization: Ballistics Research Lab
Lines: 20

The Antenna Adjust knob on the CR2021 probably does what most antenna
tuners do, control a variable capacitor or inductor (probably the latter),
forming 'transformer' which is used to match the input impedance of the
radio, (probably 30-50 ohms) front end, to the impedance of the antenna
(which varies with frequency, and for a short whip is probably several
 hundred ohms).

From comparing the 'sound' of the filter on the CR2021 with my McKay
Dymek DR-101, I would suspect 4Khz/8Khz as the filter widths, although
it could be 3/6 as well.  The 'narrow' is definetely less than 5Khz,
which is a standard 'station spacing' on shortwave.

The RF attenuator acts like about 10db per step, (which is pretty
standard for attenuators).

The 'fine tune' knob controls the frequency of the BFO, which is totally
divorced from the IF tuning frequency generated by the digital synthesizer.
I suspect getting it to act as fine tuning on AM is difficult.

						-JCP-