Ramsey Electronics R2XL1 manual

R2XL1 • 1 Ramsey Electronics Model No. R2XL1 Have you ever found yourself with two RCA outputs on your audio equipment and you somehow have t o connect them to XLR inputs. While wiring RCA leve ls directly to XLR can work, the levels will be way too low! So w hat do you do? Here is the answer to your c onversion dilemma. The R2XL1 not only conver[...]

R2XL1 • 2 RA M SEY T RA N SMIT T ER K IT S • FM100B Professional FM Stereo Transmitter • FM25B S ynthesized Stereo FM Transmi tter • MR6 Model Rocket Track ing Transmitter • TV6 Television Tra nsmitter RAMSE Y RECEI VER KI TS • FR1 FM Broa dcast Receiver • AR1 A ircraft Band Rece iver • SR2 Shortwa v e Receiver • SC1 Shortwav e Co[...]

R2XL1 • 3 R2XL1 RCA T O XLR LEVEL CONVERTER KIT Ramsey Publication No . MR2XL1 Price $5.00 TABLE OF CONTENTS Introduction .............. .............. .............. 4 Circuit Description ............... .............. .... 4 Parts List ................... .............. ............. . 7 Schematic Diagram .. .............. .............. 8 Part[...]

R2XL1 • 4 INTR OD UC TIO N Welcome t o another quali ty kit brought to you by Ramsey Electronics, Inc. This k it was designed to allo w you to connec t con sum er audio d evices to pro- fessio nal equipment with as little hassl e as possible. You would think that a product lik e this was read ily available, but it isn’t. N o w you can easily go[...]

R2XL1 • 5 The next component in line is R4. This 1K resistor in combination w ith R3 and R5 sets the gain of the first inverting opa mp stage (U1:C). An in verting opamp will take the signa l pr esented on its inpu t and flip the polarity of the sig- nal on its output giving you the inverse value of the original. In our case, the resulting output[...]

R2XL1 • 6 determine that the total gain of the circui t is 20.2 by multipl ying the series gain values together (10.1 x 2). This gives us plenty of control to get our low level RCA signals up to the higher XLR requirements. This may be more than you ever wanted to know about a preamplifier de- sign, but we aren’t done yet! The output of the two[...]

R2XL1 • 7 RA MSEY R2X L1 PA RT S LIS T Semiconductor s  6 1N4002 Rectifier Diodes (D1, 2, 3, 4, 5, 6)  1 78L12 +12V Voltage Regulator (VR1)  1 79L12 –12V Voltage Regulator (VR2)  2 LF347N Quad FET opamps (U1, 2) Resisto rs  2 10K ohm pote ntiometers (R 5, 11)  6 1K ohm resistors (brown-black-red) (R1, 2, 4, 7, 8, 10)  2 10K[...]

R2XL1 • 8[...]

R2XL1 • 9 R2XL1 PARTS LAYOUT DIA GRAM[...]

R2XL1 • 10 RAMSEY “LEARN-AS-YOU-BUILD” ASSEMBLY STRATEGY Be sure to read through all of the steps and check the boxes as you go along to be sure you don't miss any. Although you may be in a hurry to see results, before y ou switch on the power check all w iring and capacitors for proper orientation. Also check th e board for any possible[...]

R2XL1 • 11 We sincerely hope you put this kit together by carefully following the direc- tions. This project will not work as well as you wished if you just slap it together without following good assembly techniques and all of the instructions. No matter how clear we may think our manual is, if y ou have any questions give us a call at the facto[...]

R2XL1 • 12 R2XL1 ASSEMBLY We will start with the lowest profile components first and then work our way up to the largest. We do this to make assembly much ea sier since fitting a short component between two big ones can be a real pain.  1. Install D1, one of the 1N4002 diod es (black bo dy with white stripe mark ed 1N400 2). Note th at diodes [...]

R2XL1 • 13  14. Install R1, a 1K ohm resistor (brow n-black-red).  15. Install R2, a 1K ohm resistor (brow n-black-red).  16. Install R3, a 100 ohm resistor (brow n-black-brown).  17. Install R4, a 1K ohm resistor (brow n-black-red).  18. Install U1, the other LF347 quad opamp. Again ma ke sure you orien t it correctly ! It is in t[...]

R2XL1 • 14  30. Install VR2, the 79L12 negative –1 2V reg ulator. Again make sure and install it with the orientati on sho wn on the diag ram.  31. Now it is time to install the larg er components. W e w ill begin with the jacks. Ins tall J2, one of the PC mounted XLR connectors. You must be careful when installing these parts that all th[...]

R2XL1 • 15 At this point it is time to go back thro ugh and check your assembly methods for : • Diode orientation. Make sure the cathode and (the line) is in the same ori- entation as shown on the assembly diag ram. • Electrolytic capacitor orientation. Make sure the negative side of t he ca- pacitors are not in the positively marked holes ! [...]

R2XL1 • 16 PROFESSIONAL AUDIO WIRING You would thin k it would be ea sy to conn ect prof essional audio eq uipment together , but unf ortunately it ’s not. Ther e can be all sorts of issues th at come up; usually it is AC line hum in your equipment you have to deal with. This is normally caused by ground loops in the equipment. This effect can [...]

R2XL1 • 17 If neith er of these methods works and you have a source of RF nearby like a transmitter, it may be RF causing interfer ence. This is a more difficult problem to fix, bu t not impossib le. The first thing to do is move equipmen t away from the RF sour ce. The ne xt is to put t he R2XL1 ins ide o f a me tal case. The last method is to u[...]

R2XL1 • 18 TROUBLESHOO TING PROBLEM: I have no audio gain, in fact it only attenuates! SOLUTION: You will need a voltmeter to ch eck y our power. Look at pin 4 of U1 for +12 volts, and pin 11 for –12 volts. It may n ot be exactly that voltage, but +- 0.5 volts if fine. W ithout pow er applied the R2XL1 w ill pass through au- dio, but not much. [...]

R2XL1 • 19 The Ramsey Kit Warra nty Please read carefully BEFORE calling or writing in about your kit. Most problems can be solved wit hout contacting th e factory. Notice that this is not a "f ine print" warranty. We want you to understand your rights and ours to o! All Ramsey kits will work if assembled properly. T he very fact that y[...]

R2XL1 • 20 R2XL1 RCA TO XLR LEVEL CONVERTER KIT Quick Referen ce Page Guide Introduction ...... ............. ................. ...... 4 Circuit Description ....... .............. ............ 4 Parts List .... .............. ................. ............ 7 Schemati c Diagram ..................... ......... 8 Parts Layout Diagram . .............[...]