Gray.ES@Xerox.COM (02/27/86)
How to make your otherwise unselective receiver/transceiver into a real "DX machine": Replace one or all of the ceramic IF filters with something with better selectivity and stopbands of course! Here are a couple of outfits that sell these filters on a retail basis that don't require that you buy a minimum of 50 or more: Radio Plus+ 3635 Chastain Way Pensacola, Fl 32503 Radio West 3417 Purer rd. Escondido, Ca. 92505 Aiming primarily at AM filter replacements there is Radio Plus+. They advertise filter mods for the Uniden CR2021/DX-400; Kenwood R600, R1000, R2000; Icom R70 and R71A, Yaesu FRG series, plus many other receivers. Filters are of the NTK and Murata Erie Ceramic type but they are the larger ones not found in any of the commercially manufactured general coverage receivers. His prices are reasonable (19.00 to 29.00) and the filters perform quite well. I've put these in the Yaesu FRG7700, Kenwood R600 and ICOM R71A with excellent increases in selectivity and intelligibility. Filter kits are available for the new Sony 2010. SSB filters are also available. Radio West has some nice filters, primarily the Collins/Rockwell mechanical type. They sell for 150.00 which includes a small circuit board on which the filter is mounted along with a FET for a little extra gain. Considering that Collins/Rockwell is now quoting a 144.00 price tag with a 21 week lead time for sale and manufacture of any of its 455Khz filters, Radio West is a bargain. I have installed these filters in my Kenwood R1000 with excellent results. Filters in stock range from wide (9Khz at 60db) to narrow (500Hz). International Radio in Florida (I don't have the adress on me right now, but they advertise in most ham periodicals) has a excellent line of SSB/CW filters for the Icom, Kenwood and Yaesu radios at considerable savings. I installed their 2.1 Khz filter in my R71A with good results. Prices vary. A example is the ICOM FL44A SSB filter (2.4 Khz), retail is 150.00 (some sales show them at 144.00) the International Radio filter equivalent is 89.00. The 2.1 Khz model is avalable for 99.00. Happy SWL'ing Scott KD6CQ