2 meter fm receiver kit ramsey electronics model no. Fr146 keep an ear on the local repeater action from your easy chair with this simple and fun to build fm receiver. Tune the entire 2 meter band or the vhf high police and fire band. • tunes any 5 mhz portion of the 136 to 175 mhz band. • excellent...
Fr146 • 2 partial list of available kits ramsey transmitter kits • fm10a fm stereo transmitter • fm100b professional fm transmitter • fm25b synthesized fm stereo transmitter • am25 synthesized am transmitter • am1 am transmitter ramsey receiver kits • fr1 fm broadcast receiver • ar1 aircraft band re...
Fr146 • 3 fr146 2 meter fm receiver kit ramsey publication no. Mfr146 price $5.00 table of contents i ntroduction to the fr146 .............. 4 circuit description ......................... 5 parts list ........................................ 6 simplified block diagram .............. 8 parts layout...
Fr146 • 4 introduction to the fr146 fm receiver most ramsey kits can be classified as “skill level 1”. That means that our kits are intended to be sucessful for first-time kit builders. This fr146 fm receiver is best regarded as a “skill level 2” project (or at least level 1.46!) and should not be t...
Fr146 • 5 use bright lighting. A magnifying lamp or bench-style magnifier may be helpful. Do your work in stages, taking breaks to check your work. Carefully brush away wire cuttings so they don't lodge between solder connections. Fr146 circuit description vhf signals from the antenna are amplified ...
Fr146 • 6 parts list inductors 2 small 1 1/2 turn coils (l1,l2) 1 slug-tuned 3 1/2 turn coil [orange color] (l3) 1 shielded transformer coil [marked lb 53303] (l4) semiconductors and ic's 1 2sc2498 or 2sc2570a transistor (q1) 3 2n3904 transistor (q2,q3,q4) 1 sa602 8-pin ic (u1) 1 mc3359 18-pin fm re...
Fr146 • 7 3 4.7 or 10 uf electrolytic (c15,30,36) 4 100 to 220 uf electrolytic (c14,32,33,35) controls and hardware 1 printed circuit board 3 10k ohm potentiometer (r1,r2,r3) 1 dpdt push switch (s1) 1 pc mount rca jack (j1) 1 pc mount subminiature speaker jack (j2) 1 9-volt battery bracket 1 9-volt ...
Fr146 • 8 u2, 3359 fr146 block diagram u1 sa602 mixer.
Fr146 • 9 fr146 parts layout diagram.
Fr146 • 10 ramsey “learn-as-you-build” kit assembly: we have a twofold "strategy" for the order of the following kit assembly steps. First, we install parts in physical relationship to each other, so there's minimal chance of inserting wires into wrong holes. Second, whenever possible, we install in...
Fr146 • 11 further component installation all "directions" on the pc board (ie: right, left, above, below and so forth) assume orientation of your board as shown in the parts layout diagram. Therefore the rear of the board (connectors) is the lower end, and the front (controls) is the upper end. 1. ...
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Fr146 • 14 dot, or notch. Before soldering, make sure that the ic or socket is perfectly fflat against the top of the pc board. Install u1, the sa602, in accord with the preceding directions. ❒ 19. Install fl1, the ceramic filter. This component looks like a capacitor with 3 leads and may be install...
Fr146 • 15 progress summary so far, you have wired the tuned input from the antenna, the rf preamplifier, and the sa602 mixer-oscillator, including the varactor tuning circuit. The work you have done has actually formed a simple receiver capable of tuning in vhf signals of all kinds and converting t...
Fr146 • 16 4. Mc3359 fm ic and associated components ❒ 55. Install r17, 10k ohms [brown-black-orange] ❒ 56. Install r14, 33k ohms [orange-orange-orange] ❒ 57. Install c24, .001 uf [marked .001, 102, or 1 nf]. ❒ 58. Install c25, .001 uf [marked .001, 102, or 1 nf]. ❒ 59. Install c26, .01 uf [marked ....
Fr146 • 17 ❒ 73. Install r16, 100k ohms [brown-black-yellow]. ❒ 74. Install r15, 470k ohms [yellow-violet-yellow]. 5. Final connections: the lm386 audio ic stage you now have a working fm receiver ready for adjustment. The output of the mc3359 fm ic simply needs to be boosted to listening level. A f...
Fr146 • 18 testing, alignment and adjustment to prepare the fr146 fm vhf receiver for reliable monitoring operation, you will need these basic tools: ❒ 1. A useful vhf signal source. ❒ 2. Hexagonal, non-metallic coil slug alignment tool for l3. ❒ 3. Small screwdriver to adjust l4. 1. Signal source: ...
Fr146 • 19 further alignment now consists of adjusting the oscillator coil l3 to permit the tuning control (r1) to cover the 5 mhz. Segment between 135 and 175 mhz of primary interest to you. Assuming you wish to adjust for the two meter 144-148 mhz amateur band, adjust l3 until you hear your intend...
Fr146 • 20 locating the led immediately above the on-off switch is logical and ideal. The simplest way to make a good installation is to drill a neat hole just slightly smaller than the diameter of the led. Then, enlarge the hole a little bit at a time just enough to let the led be pressed in and he...
Fr146 • 21 fr146 troubleshooting hints ramsey fr-series fm receivers are among our most widely-used and popular kits. The circuit itself, assembly and use are "cut-and-dried." if your receiver does not work, there is probably either an error in assembly or a defective part. Following is some help in...
Fr146 • 22 hearing about significant performance improvements, we do not recommend casual modification attempts. However, there is one practical customization which could be undertaken by experienced vhf experimenters who wish to take advantage of the ne602's ability to accept a crystal resonator in...
Fr146 • 23 the ramsey kit warranty please read carefully before calling or writing in about your kit. Most problems can be solved without contacting the factory. Notice that this is not a "fine print" warranty. We want you to understand your rights and ours too! All ramsey kits will work if assemble...
R146 • 24 fr146 2 meter fm receiver kit quick reference page guide i ntroduction to the fr146 ............... 4 circuit description .......................... 5 parts list ........................................ 6 simplified block diagram ............... 8 parts layout diagram .................... ...
