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starman wrote:
Mike Maghakian wrote: all these issues are covered by easy fixes, if you don't want to do them , then the DX-394 is NOT the radio for you. My 394 is selective (mod), quiet (inherently), has no pops(mod) and is a very nice radio. I would pay a lot lot more than $50 for one and buy a dozen at a time if I could. What are the main weak points of the DX-394 that need to be addressed to make it a decent receiver? By joining the RADIOSHACKDX394 SIG at http://groups.yahoo.com/group/RADIOSHACKDX394/, you will automatically receive the DX-394 FAQ and an index to over 50 mods. From the FAQ: Best Mods Much depends on your listening objectives and the radio frequency environment in your area. The DX-394 is certainly deficient in the areas of selectivity, overload and shielding so these are areas of improvement that are probably of common interest and benefit. Other modifications may be of more special interest. Here are the key mods and tips: 1. Frank Cathell's Crosstalk mods are a must to correct a design deficiency in all models that results in strong stations 15-40 kHz away from the desired frequency being detected as though they were on frequency. 2. One of the IF filter mods is also highly advisable - Frank's "Poor Man's Kiwa" that changes the logic to force the narrower filter in all modes is the easiest. 3. The DX-394 is susceptible to overload from strong signals and internally generates multiple appearances of them. Countermeasures depend on the desired frequency band and the frequencies of the offending signals: a) For SW listening bothered by LW/MW overload, a 1.8 MHz outboard high pass filter is a great start. b) For SW listening suffering from SW overload, a passive pre-selector (tuned or fixed bandpass) or a high quality active pre-selector may help on SW bands removed from the interfering frequencies. c) For LW and MW listening, it may be necessary to shield or disable the built-in antenna and use a tuned loop external antenna for added selectivity and directionality to discriminate against the strong signals. d) An outboard attenuator may also be necessary in difficult conditions in any of these cases. Fortunately, apart from shielding or disabling the ferrite antenna, all of these are tips, not modifications of the DX-394, but are covered under Mods because overload is such a common problem. 4. Shielding is also essential for the suppression of interference picked up from computers and CRT's operating in close proximity to the DX-394. Its plastic case is useless in this respect - SW signals can be picked up even with the whip antenna removed. Tom Holden's "Ultimate Shields" mod is among the most effective for both RF and magnetic screening Tom |