Instruction/ maintenance manual of the product HR40 Ramsey Electronics
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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 d.
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.
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 .....
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.
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.
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.
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 .
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.
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.
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).
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.
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.
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.
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.
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.
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.
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 .
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.
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.
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.
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 addition.
HR40 • 24 CONSTRUCT ION NOTES:.
HR40 • 25.
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 .
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.
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 ............
An important point after buying a device Ramsey Electronics HR40 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Ramsey Electronics HR40 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Ramsey Electronics HR40 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Ramsey Electronics HR40 you will learn all the available features of the product, as well as information on its operation. The information that you get Ramsey Electronics HR40 will certainly help you make a decision on the purchase.
If you already are a holder of Ramsey Electronics HR40, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Ramsey Electronics HR40.
However, one of the most important roles played by the user manual is to help in solving problems with Ramsey Electronics HR40. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Ramsey Electronics HR40 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
