Ramsey Electronics HR40 manual

HR40 • 1 40 ME TE R ( 7. 0 MH Z ) 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, ea sil y r etuned • Uses the popular SA 602 IC chip for outstanding sensitivity and efficient o peration[...]

HR40 • 2 RA MSEY TRA NSMIT TER KITS • FM100B Professional FM Ste reo Transmitter • FM25 B Synthesize d Stereo Tra nsmitter • A M1, AM25 AM Transmitters • TV6 T elevisio n Transmitter RAMSE Y RECEI VER KI TS • FR1 FM Br oadc ast Re cei ver • AR1 A ir craft Band Recei ver • SR2 Sho rtwave R eceiver • AA7 Ac t i ve An t e n n a • S[...]

HR40 • 3 HR40 AMA TEUR 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 diagram ....... ................. 9 Parts layout[...]

HR40 • 4 INTR OD UC TIO N: 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 y ou like plent y o f action and DX (long distance) communications, the 40 meter Ha m band is the place to be. Almost 24 hours a day there’s something in[...]

HR40 • 5 This receiver circuit is ideal for discovering ju st how simple a t rue “Communications Receiver” can be. Th at’s right- there is a BIG difference between the Ra m sey 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 f ar the easiest to build of all the Ramsey k[...]

HR40 • 6 called “microphonics” w hi ch is a phenomenon where almost any thing in the physical circuitry of the receiver can act as a sort of microphone or aud io sound pick up. To uch or bum p such r adios and you will hear a t hump or ring in the speaker or earphones. Still anothe r problem is that of AC line hum whenever a n unre gulated po[...]

HR40 • 7 PARTS SUPPLIED WITH THE HR40 KIT: CAPACITORS: 1 .001µF disc capacit or [marke d 102, .001 or 1nF] ( C3) 3 100pF disc capacit or [marked 100 or 101K] (C1,C2,C4) 3 .01µF disc capacitor [marked 103 , .01 or 10nF] (C5,C6,C7) 2 4.7 to 10µF electroly tic c apacitor (C8,C9) 3 100-220µF electroly tic capacitor (C10,C11,C12) RESISTORS: 3 10K [...]

HR40 • 8 "LEARN-AS- YOU-BUILD" ASSEMBLY STRAT EGY: 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 boar d sim ple, we will not be able to fully describe each individual component’s function as yo[...]

HR40 • 9[...]

HR40 • 10 PA RT S LA YOU T:[...]

HR40 • 11 RECEIVER ASSEMBLY:  1. Install the RCA antenna ja ck , J1. Solder all four points.  2. Install C5, a .01µF cera mic 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, the RF gain control. Insert it int[...]

HR40 • 12 capacitor is a first s tep in setting up th e resonant frequen cy of the SA602 ’s internal oscillato r, using the resonant LC circ uit to be created along with C1, C3 and L1.  12. Install C1, 100pF disc capacito r (marked 100 or 101K).  13. Install C3, .001µF disc capacitor (marked 102 or .001 or 1nF).  14. Install L2, shiel[...]

HR40 • 13  29. Install speaker jack J2. This jack is a 2.5mm type and mates w ith 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 cla mp an d through the PC boar d. Solder the leads firmly to the board and to the battery clam p. D[...]

HR40 • 14 INITIAL TESTING OF YOUR HR40: You’re now re ad y to power up and test your HR40, but before you b egin take some time to sweep off your bench of any loose c omponent leads or solder splashes. A clean work area not o nl y makes testing less frustrating but also less prone to proble m s. REQUIRED FOR INITIAL T ESTING AND ALIGNMENT: A kn[...]

HR40 • 15 Align men t: Turn on whatever re f erence signal source you plan to use. This can be a regular transceiver keying a few milli watts 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 receive r. If you are without any reference signal what s oever but have [...]

HR40 • 16 USING YO UR RECEIVER: In your first tests, you might f eel that tuning in CW and SSB stations by turning the control sh af t seems tr ick y. Don 't despair! The addition of a simple knob to the final version of your kit w ill result in more comfortable tuning right away. Also, the larger the knob, the easier th e tuning is. Even sm[...]

HR40 • 17 A better operating arrangement will consist of a T-R switch, either a manual switch or break-in delay relay circu it. This switching circuit can disconnect the SA602 audio output at the vo lum e control, and switch in a pleasant oscillator pitch (keying sidetone) which is amplified to listening leve l by LM386. The Ramsey Electronics Un[...]

HR40 • 18 you wish to install the LED in your enclosure. Locating the LED immediately above the on-off sw itch is ideal. The si mplest way t o make a neat insta llation is to dri ll a hole just si ghtly smaller than the dia meter of the LED. T hen, enlarge t he hole a little bit at a time, just enoug h to let the LED be pressed in and held f irml[...]

HR40 • 19 TROU BL ESH OO TIN G TI PS : PROBLEM: ALL signals are chirpy and unstable. SOLUTION: Sorry to have to sa y it , bu t this condition is only caused by a weak battery ! Use a fresh alkaline cell. Any strong signal forces the audio c ircuit to r ob voltage f rom the os cillator, which causes the instability . PROBLEM: Occasionally good but[...]

HR40 • 20 GENERAL NOTES FOR EXPERIENCED QRP BUILDERS: W e at Ramsey Electronics deliberatel y designed the HR-series of DC receivers to be easil y available, aff ordable a nd buildable b y any pers on willi ng to follow the assembly di r ections. To achieve this goal, the current models, with direct coupling of the SA602 to the LM386 operating wi[...]

HR40 • 21 In planning a n y ‘bandspread’ improvemen t, 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 ca pacit ance. The spread is typically about 30 to 40pF. f rom min[...]

HR40 • 22 OTHER METHODS OF DI AL CALIBRATION: A easy way of making your ow n dial is to paste a s mall rectangle of paper behind the tuning d ial knob. Then as you tune in different f requencies, pencil in on the paper the received frequency . Or a sim ple logging scale may be affixed behind the tuning knob on the front panel. A logging scale is [...]

HR40 • 23 frequency response, but is does significantly boost the output of the SA602 reaching the LM386 audio amplifier IC. Instead o f the traditiona l transistor audio preamp circuit, an additional LM386 is u sed in its minimum gain configuration (gain of 40), plus one electrolytic capacitor (1 to 10 uF) to achieve minimum parts a nd PC-board [...]

HR40 • 24 CONSTRUCT ION NOTES:[...]

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HR40 • 26 The Ramsey Kit W arranty Please re ad caref ully BEFORE calling or w riting in abou t your kit. Mo st problem s can be solved w ith out co ntacting the fact ory. Notice th at this is not a "fine print " warranty . W e w ant you t o understand your rights and ours too! All Ramsey kits will work if assembled pro perl y . The ver[...]

HR40 • 27 3. FACTORY REP A IR OF A SSEMBLED KITS: To qualify for Ramsey Electronics fa ctory repair, kits MUST: 1. NOT be assembled with a cid core solder or flu x. 2. NO T be mo difie d in any manne r. 3. BE retu rned in fully-assembled form, not partially assembled. 4. BE accompanie d b y the proper repair fee. No repair w ill be undertaken unt[...]

HR40 • 28 HR40 AMATEUR RECE IVER KIT Quick Referenc e Page Guide Introduction to the HR40 ................. 4 Circuit description ............ .............. .6 Parts list ..................... ............. ........ 7 Schematic diagram .................... ..... 9 Parts layout ...................... ............. 10 Assembly instructions .......[...]