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- HR40
- User Manual
Ramsey Electronics HR40 User Manual - Parts Layout:
Summary of HR40
Page 1
Hr40 • 1 40 meter (7.0 mhz) all mode receiver kit ramsey electronics model no. Hr40 small in size but big in features: • easily tunes ssb, cw, rtty and am • smooth varactor tuning of any desired 250khz segment of the 40 meter band, easily retuned • uses the popular sa602 ic chip for outstanding sens...
Page 2
Hr40 • 2 ramsey transmitter kits • fm100b professional fm stereo transmitter • fm25b synthesized stereo transmitter • am1, am25 am transmitters • tv6 television transmitter ramsey receiver kits • fr1 fm broadcast receiver • ar1 aircraft band receiver • sr2 shortwave receiver • aa7 active antenna • s...
Page 3: Hr40 Amateur
Hr40 • 3 hr40 amateur receiver kit ramsey publication no. Mhr40 price $5.00 table of contents introduction to the hr40 ................ 4 about direct conversion ................ 5 circuit description .......................... 6 parts list ......................................... 7 schematic diagr...
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Hr40 • 4 introduction: our hr40 and hr80 models are thought of as “best for beginners” because hams with a novice or technician licenses can operate cw in the 80 and 40 meter bands. If you like plenty of action and dx (long distance) communications, the 40 meter ham band is the place to be. Almost 2...
Page 5
Hr40 • 5 this receiver circuit is ideal for discovering just how simple a true “communications receiver” can be. That’s right- there is a big difference between the ramsey hr40 and other simple short wave radio circuits we can try to build. Yet it is very easy to build. Our hr-series are by far the ...
Page 6
Hr40 • 6 called “microphonics” which is a phenomenon where almost anything in the physical circuitry of the receiver can act as a sort of microphone or audio sound pickup. Touch or bump such radios and you will hear a thump or ring in the speaker or earphones. Still another problem is that of ac lin...
Page 7
Hr40 • 7 parts supplied with the hr40 kit: capacitors: 1 .001µf disc capacitor [marked 102, .001 or 1nf] (c3) 3 100pf disc capacitor [marked 100 or 101k] (c1,c2,c4) 3 .01µf disc capacitor [marked 103 , .01 or 10nf] (c5,c6,c7) 2 4.7 to 10µf electrolytic capacitor (c8,c9) 3 100-220µf electrolytic capa...
Page 8
Hr40 • 8 "learn-as-you-build" assembly strategy: to help you learn just what exactly is going on we'll discuss the purpose of most of the components or groups of components as we go along. Since we are trying to keep assembly of the board simple, we will not be able to fully describe each individual...
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Hr40 • 9.
Page 10: Parts Layout:
Hr40 • 10 parts layout:.
Page 11
Hr40 • 11 receiver assembly: 1. Install the rca antenna jack, j1. Solder all four points. 2. Install c5, a .01µf ceramic disc signal coupling capacitor. This capacitor brings the signal up to the front of the pc board. Notice the long pc trace from j1 through c5 to r1 3. Install potentiometer r1, th...
Page 12
Hr40 • 12 capacitor is a first step in setting up the resonant frequency of the sa602’s internal oscillator, using the resonant lc circuit to be created along with c1, c3 and l1. 12. Install c1, 100pf disc capacitor (marked 100 or 101k). 13. Install c3, .001µf disc capacitor (marked 102 or .001 or 1...
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Hr40 • 13 29. Install speaker jack j2. This jack is a 2.5mm type and mates with any 2.5mm plug as found on virtually all mini earphones. 30. Install the 9-volt battery clamp. Use a scrap component lead to loop through the two holes in the clamp and through the pc board. Solder the leads firmly to th...
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Hr40 • 14 initial testing of your hr40: you’re now ready to power up and test your hr40, but before you begin take some time to sweep off your bench of any loose component leads or solder splashes. A clean work area not only makes testing less frustrating but also less prone to problems. Required fo...
Page 15
Hr40 • 15 alignment: turn on whatever reference signal source you plan to use. This can be a regular transceiver keying a few milliwatts into a dummy load, a crystal oscillator or a signal generator. Or, you can look for a known signal that you have tuned in on another receiver. If you are without a...
Page 16
Hr40 • 16 using your receiver: in your first tests, you might feel that tuning in cw and ssb stations by turning the control shaft seems tricky. Don't despair! The addition of a simple knob to the final version of your kit will result in more comfortable tuning right away. Also, the larger the knob,...
Page 17
Hr40 • 17 a better operating arrangement will consist of a t-r switch, either a manual switch or break-in delay relay circuit. This switching circuit can disconnect the sa602 audio output at the volume control, and switch in a pleasant oscillator pitch (keying sidetone) which is amplified to listeni...
Page 18
Hr40 • 18 you wish to install the led in your enclosure. Locating the led immediately above the on-off switch is ideal. The simplest way to make a neat installation is to drill a hole just sightly smaller than the diameter of the led. Then, enlarge the hole a little bit at a time, just enough to let...
Page 19
Hr40 • 19 troubleshooting tips: problem: all signals are chirpy and unstable. Solution: sorry to have to say it , but this condition is only caused by a weak battery! Use a fresh alkaline cell. Any strong signal forces the audio circuit to rob voltage from the oscillator, which causes the instabilit...
Page 20
Hr40 • 20 general notes for experienced qrp builders: we at ramsey electronics deliberately designed the hr-series of dc receivers to be easily available, affordable and buildable by any person willing to follow the assembly directions. To achieve this goal, the current models, with direct coupling ...
Page 21
Hr40 • 21 in planning any ‘bandspread’ improvement, it is useful to understand exactly how varactor tuning works. The control level varies the amount of dc voltage applied to the diode. The highest produces the lowest capacitance, while the lowest voltage yields the highest capacitance. The spread i...
Page 22
Hr40 • 22 other methods of dial calibration: a easy way of making your own dial is to paste a small rectangle of paper behind the tuning dial knob. Then as you tune in different frequencies, pencil in on the paper the received frequency. Or a simple logging scale may be affixed behind the tuning kno...
Page 23
Hr40 • 23 frequency response, but is does significantly boost the output of the sa602 reaching the lm386 audio amplifier ic. Instead of the traditional transistor audio preamp circuit, an additional lm386 is used in its minimum gain configuration (gain of 40), plus one electrolytic capacitor (1 to 1...
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Hr40 • 24 construction notes:.
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Hr40 • 25.
Page 26: The Ramsey Kit Warranty
Hr40 • 26 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 assembled...
Page 27: 4. Refunds:
Hr40 • 27 3. Factory repair of assembled kits: to qualify for ramsey electronics factory repair, kits must: 1. Not be assembled with acid core solder or flux. 2. Not be modified in any manner. 3. Be returned in fully-assembled form, not partially assembled. 4. Be accompanied by the proper repair fee...
Page 28: Ramsey Model No. Hr40
Hr40 • 28 hr40 amateur receiver kit quick reference page guide introduction to the hr40 .................4 circuit description ...........................6 parts list ..........................................7 schematic diagram .........................9 parts layout ..................................