-
Ramsey Electronics PR20 - page 1
PR20—1 220 MHz LOW NOISE PREAMP KIT • 16 db Gain, 1 db Noise Figure • Runs on 9 to 15 VDC • Hi-Q tuned input to reduce overload • Small size to fit in any rig • The most popular preamp kit in the USA! • Easy 15 m inute as sembly Perk up your reception on 220 MHz with this easy-to-build an d install kit. Works well with any radio - esp ...
-
Ramsey Electronics PR20 - page 2
PR20—2 INTRODUCTION T O THE PR20 LOW NOISE PREAMPLIFIER A “preamplifier” gives an initial boost, measured in decibels, to the leve l of a signal before it is further processed by tuned circuits, filters, amplifiers, mixers, detect ors, or other circuit stages. Preamp s may be designed for either RF or audio use and ma y be either tuned or bro ...
-
Ramsey Electronics PR20 - page 3
PR20—3 CIRCUIT DESCRIPTION L1 and C2 form a tuned input filter f or the preamp to reject out-of-b and signals. T he 3 db bandwidth of this filter is 6MHz. L1 is adjustable for pe ak performance. The 2SC2498 transistor is a bipolar silicon NPN low noise UHF/VHF amplifier in a T O-92 case suitable for service up to 5 GHz, with maxi mum device dissi ...
-
Ramsey Electronics PR20 - page 4
PR20—4 P ARTS SUPPLIED WITH PR20 KIT CAP ACITORS 2 2 or 2.2pF disc capacitor (C1,2) 1 10pF disc cap acit or (C3) 1 100pF disc cap acitor [m arked 100 or 101] (C4) 1 .01uF disc cap acitor [may be marked .01, 103, or 10n F] (C5) RESISTORS 1 470 ohm [yellow-violet-brow n] (R1) 1 100K ohm [brown-black-y ellow] (R2) OTHER COMPO ...
-
Ramsey Electronics PR20 - page 5
PR20—5 RAMSEY PR20 PRE-AMP P ARTS LA YOUT NOTE FOR PR-20: Disregard C6 * ...
-
Ramsey Electronics PR20 - page 6
PR20—6 PR20 PRE-AMP A SSEMBL Y PROCEDURE Soldering nine pa rts to a PC board is not a big job, but good perfo rmanc e of the PR20 requires attention to keeping all leads as short and neat as possible. The order of p arts installation is not critical for this and othe r small kit s, so the purpose of the following suggested order of assembly is ju ...
-
Ramsey Electronics PR20 - page 7
PR20—7 3. Install C4, 100pF (m arked 100 or 101). 4. Install C5, .01uF (marked .01 or 103 or 10nF). Disc capacito r C5 is the byp ass capacitor for the DC volt age supply points on the PC board. 5. Install Q1, 2SC2498. Press Q1 into it s respective loca tion on the PC board, which should be quite o bvious by the placement of the previ ...
-
Ramsey Electronics PR20 - page 8
PR20—8 two mechanical point s after making sure that L1 is presse d firmly against the component side of the PC board. PROGRESS SUMMAR Y : The wiring of y our Ramse y PR series preamp PC board is now complete. It will t a ke you less th an a minute to completely re check every single soldering connection as well as for the appropriate part inst a ...
-
Ramsey Electronics PR20 - page 9
PR20—9 TESTING A ND A D JUSTMENT With your preamp installed betw een antenna and receiver , the on ly adjustment needed is the obvious one: peaking L1 for ma ximum signal strength. This ma y require more p atience than most of us would think, because the adju stment should be ma de on a weak signal transmitting long enough to permit the adjustmen ...
-
Ramsey Electronics PR20 - page 10
PR20—10 PR20 ON-OFF SWITCHING SUGGESTION Depending on your particular application an d intended frequency , yo u may wish to use a DPDT pow er switch w ith one pole c ontrolling volt age and t he other pole connecting the input and output of the PR20 when the DC su pply volt age is in t he “OFF” position. This setup is very practical when you ...
-
Ramsey Electronics PR20 - page 11
PR20—11 A 220 MHz “ACTIVE A NTEN N A ” For situations where a simple indoor receiving antenn a is needed, the P R20 preamp will add considerably improved performance to a wh ip antenna adjusted to 1/4 or 5/8 wave. A nd, for a very well engineered true active antenna fo r both HF and VHF at a break-through low price, take a look at our ne w mo ...
-
Ramsey Electronics PR20 - page 12
PR20—12 2SC2498 CHAR A CTERISTICS: The 2SC2498 transistor is a bipolar silicon NPN low noise UHF/VHF amplifier in a TO-92 case, suitable for service up to 5GHz, with maximum device dissipation of 600 milliwatt s. Other max imum ratings: Collector -to-Base V oltage: 25 V Collector-to-Emitter V o lt age: 12 V Base-to-Emitter V o ltage: 3 V Maximum ...
-
Ramsey Electronics PR20 - page 13
PR20—13 TROUBLESHOOTING GUIDE The only possible causes for malfunction of th e PR20 are faulty or incorrectly inst alled part s. Re-check your work. T ransistor re placement information is provided. Poor performance such as oscillation can be caus ed by bad p arts-mounting (exc essive lead length of resistors or capacito rs). Erratic operation w ...
-
Ramsey Electronics PR20 - page 14
PR20—14 THE RAMSEY PR2: THE UL TIM A TE BRO ADBAND PREA M PLIFIER After y ou find out how practical a well-built PR 20 can be for 220MHz op erating, you will b e quite impressed with the “all bands” higher gain (also with very low noise) plus the convenient AC po wer supply , BNC I /O conn ectors and LED ON-OFF indicator of the Ramsey PR2, av ...
-
Ramsey Electronics PR20 - page 15
PR20—15 The Ramsey Kit Warra nty Please read carefully BEFORE calling or writ ing in about your kit. M ost problems can be solv ed w i thout contactin g the factory. All Ramsey kits will work if assembled properly. The very fact th at your kit includes this new manual is your assurance that a team of knowledgeable people ha ve field-tested severa ...
-
Ramsey Electronics PR20 - page 16
PR20—16 Published by Ramsey Electronics, Inc. Copyright 1994 All rights reserved. Ram sey Electronics, Inc. 590 Fisher s Station Drive Victor, NY 14564 Phone (585 ) 924-4560 Fax (585) 924-4555 www.ramseykits.com Call or write for our full line cat alog! P ART I AL LI S T O F AV AI L AB L E K IT S RAMSEY TRANSMITTER KITS • FM10 A , FM 25B ...
Hai una domanda su Ramsey Electronics PR20?
Utilizza il modulo sottostante
Se non hai risolto il problema con Ramsey Electronics PR20 con l'aiuto del manuale che hai trovato, fai una domanda utilizzando il modulo sottostante. Se un utente ha avuto un problema simile con Ramsey Electronics PR20 è probabile che voglia condividere il modo di risolverlo.