RSHAPIRO@BBNA.ARPA (06/15/84)
From: Richard Shapiro <RSHAPIRO@BBNA.ARPA> Now that we've seen a review of the MFJ-1020, is anyone prepared to offer reviews of some other active antennas? In particular I'm wondering about the Dymek DA-100D and the Sony AN-1 (particularly for apartment use). How about tuners for wire antennas? Comparisons/contrasts appreciated. Thanks, richard shapiro/bbn cambridge,mass -------
parnass@ihu1h.UUCP (Bob Parnass, AJ9S) (02/15/86)
> > I have recently returned to the hobby of shortwave listening after an absence > > of over 10 years........... > > > > I live in a third floor apartment. Currently I am using a 30' length of wire > > which lies around the perimeter of my listening room. I am not permitted > > wires outside my window, nor am I allowed to hang any wires from my balcony... > > > > I am considering purchasing a remote active antenna, such as the MFJ 1024. > > My other alternative is to purchase an antenna tuner and attach my 30' > > length of wire to it........ > > > > My question is: Which will give me better performance, an outdoor-mounted > > active antenna, or an indoor 30 foot longwire antenna with an antenna tuner?.. > > I am also interested in the same information. There are two tuners that I > know of that are for random longwire antennas. One is by MFJ ( I forget the > model number) and the Mini-Tun by Grove Enterprises. Does any body have > information on these tuners? > > > > Jerry Ruhno > epsilon!mb2c!gbr x I posted an article on the MFJ 1020 indoor active antenna over a year ago, but have since replaced my ICOM R70 with an R71A and Drake R7, and moved to a house with a lot of land. I don't know how the MFJ 1024 outdoor active antenna stacks up against the indoor model, but I can recommend the indoor unit as long as you connect 20 or so feet of wire to it. In my case, the wire was lying on the floor inside my 2nd floor apartment, then wrapped around the inside of a window frame. Being tucked between the plaster wall and the frame, the wire was hidden from view. I still use my MFJ occasionally as a preamp for my out- door 75' wire. It seems to perform as well as, or better than, my Ameco FET preamplifier. MFJ offers a limited time free trial of MFJ equipment if bought directly from MFJ. A friend also wonders about the 1024 and said he will take advantage of the free trial. He bought a 1020A last week and uses it with a short outdoor wire from his apartment. If you do buy the MFJ 1020, be sure to run it from 12 VDC rather than 9 VDC, to get best results. =============================================================================== Bob Parnass, Bell Telephone Laboratories - ihnp4!ihu1h!parnass - (312)979-5414 ARTICLE FOLLOWS: MFJ 1020 Active (Indoor) Antenna Bob Parnass, AJ9S The MFJ 1020 Active Antenna consists of a telescoping antenna and a preselector-type circuit inside the now familiar beige and wood grain cabinet. The frequency coverage of approximately 200 KHz to 30 MHz is divided into 5 bands. A small, external power supply is required, but not provided. The 1020 lists for $80 new, but I purchased it at a hamfest for $20, and performed one minor repair (replaced a fiber washer at the base of the telescoping antenna). I use this unit with an ICOM R-70 general coverage receiver. Overall, the MFJ 1020 works better than expected, although still not as good as an outdoor antenna. The Bad News Phono jacks are used rather than the SO-239 type. The inclusion of an LED indicator lamp in the 1020 really precludes the prolonged use of any internal bat- tery. One problem with my particular unit is that, despite the dial markings, coverage ends at about 28.5 MHz (rather than 30.0 MHz). There is no simple trimmer capacitor that can be adjusted as a remedy. One of these days (yawn), I'll have to trim an inductor. Active antennas are more prone to electrical interfer- ence. A photoelectric night light in an adjacent room causes a high QRN level, due to the SCR in the dimming circuit, and must be disabled during listening periods. Emissions from the horizontal oscillators of TV sets in the building also cause problems. Use of a narrow band (tuneable, in this case) antenna makes "instant QSY" impossible. One cannot make full use of the broadband capabilities of the new generation of general coverage receivers. This is a shame, espe- cially if one has a receiver such as the ICOM R-71 or the Kenwood R2000 which contain several memories. -- =============================================================================== Bob Parnass, Bell Telephone Laboratories - ihnp4!ihu1h!parnass - (312)979-5414