Ramsey Electronics MX10 manual

MX10 Page 1 Ramsey Electronics Model No. MX10 Now here’s the simple easy to use mixer for all of you home brew DJs out there! This mixer has all of the feat ures you will ever need to mix audio as the professionals do - in a small compact size! Perfect for DJing on the desktop transmitter, making car tapes, mixing for a wedding or anywhere else a[...]

MX10 Page 2 RA MSEY T RA NSM ITT ER KIT S • FM10 A , FM25B FM Stereo Tr ansmitters • AM1, AM25 AM Transmitter s • TV6 Tele vision Transmitter RAMSE Y RECEI VER KITS • FR1 FM Broa dcast Receiver • AR1 A ircraft Band R eceiver • SR2 Short-wave Receiver • A A7 Ac t i ve An t en n a • SC1 Short-wav e Co nverter RAMSE Y HOBB Y KITS • S[...]

MX10 Page 3 MX10 STEREO THREE INPUT MIXER Ramsey Publication No. MMX10 Price $5.00 Table of Contents Introduction . .................... ...............4 Circuit Description ................ ...........5 MX10 Parts List ................... .........10 Assembly Procedure .....................11 Schematic Diagram ......................16 Initial Test[...]

MX10 Page 4 INTR ODU CTI ON TO THE MX10 Seeing the need for a high fidelity low noise mixer to be used with our micropower transmitters, we came up wi th this easy to build com pact mixer. The small size lends to the small size of the transmitter for portability. You can easily fit an entire radio station inside of a briefcase, just try that with e[...]

MX10 Page 5 There are three inputs to this amplifier. The 10K ohm resistors determine how much gain each of the inputs has, and th e 33K resistor sets the over all gain. To find the gain of each branch, there is a simple equ ation: RF = 33K and Rin is any one of the th ree branch resistors. In this case the gain is 33 K/10K = 3.3. To f ind the outp[...]

MX10 Page 6 The next stage of the microphone amplifier has two diodes in the feedback loop. What ar e these for? you ma y ask. W ell they are called clipping diodes . Diodes hav e a property of needing abou t .7 volts across them if the forward bias direction before they turn on. On signa ls under .7V P/P, the gain of the second stage is determined[...]

MX10 Page 7 circuits. Th e earphone am plifiers LM 386s have quite a bit of ki ck to them, which should be more than enough to out power most DJ systems. The peak hold met ers serve the f unction of displaying pea k amplit udes in your audio so y our eye can see them. Normally a short duration pu lse such as a drum beat or strum of a guitar has a v[...]

MX10 Page 8 RAMSEY “LEARN-AS-YOU-BUILD” ASSEMBLY STRATEGY Be sure to read through all of the steps, and check th e boxes as you go to be sure you di dn't miss an y important steps. Although y ou may be in a hurry to see results, before you switch on the pow er check all wiring and capacitors for proper orientation. Also check the board for[...]

MX10 Page 9 As with all Ramse y kits, we want to mount the parts AS LOW AS POSSIBLE to the board. A 1/4” lead len gth on a resistor not m ounted c lose to the board ca n act as an inductor or an antenna, causing all sorts of problems in y our circuit. Be aware thoug h that if there are stand up components in your circuit, they don’t need to be [...]

MX10 Page 10 RAMSEY MX10 PARTS LIST Semiconductor s ❒ 3 LF347 Dual operationa l amplifiers (U4,5,6) ❒ 2 LM386 Audio power amplifiers (U2,3) ❒ 2 LM3915 LED bargraph drivers (U7,8) ❒ 4 1N4002 type diodes (black epoxy body with w hite stripe)(D29,31,34,35) ❒ 6 1N4148 type diodes (small glass body w ith black stripe)(D1,2,5,6,8,19) ❒ 10 Sma[...]

MX10 Page 11 ASSEMBLY OF THE MX10 Now we are getting to the good stuff-assembling the MX10. We will begin by mounting first the low parts, beginning w ith the parts on the side of the board labeled as “PARTS” side on the PC b oar d. When we are finished with that side, we will begin to install parts on th e “CONTROL” side of the board. This[...]

MX10 Page 12 ❒ 18. Install R27, a 10K ohm resistor (brown -black-orange). ❒ 19. Install R28, a 10K ohm resistor (brown -black-orange). ❒ 20. Install D1, a 1N4148 type diode (orange body with black stripe). Make sure that the catho de end (with the stripe) is inst alled in the sam e orientation as where the “arrow” is pointing to the strip[...]

MX10 Page 13 read y to continue with the rest of the project . ❒ 39. Install R54, a 10K oh m resist or (brown-black-or ange). ❒ 40. Install R52, a 10K oh m resist or (brown-black-or ange). ❒ 41. Install R82, a 10K oh m resist or (brown-black-or ange). ❒ 42. Install R70, a 100K ohm resistor (brown-black-yellow). ❒ 43. Install D6, a 1N4148 [...]

MX10 Page 14 ❒ 59. Install R89, a 68K oh m resist or (blue-gra y -oran ge). ❒ 60. Install R43, a 100K ohm resistor (brown-black-yellow). ❒ 61. Install R67, a 180 ohm resistor (brown-gray-brown). ❒ 62. Install R76, a 10K oh m resist or (brown-black-or ange). ❒ 63. Install R77, another 10K ohm resistor (brow n-black-orange). ❒ 64. Install[...]

MX10 Page 15 parts, we will quit going from left to ri ght, top to bo ttom and begin to install parts cl ose to one another. ❒ 81. Install C1, a 10uF electrolytic capa citor. Notice this is the first capacitor of this ty pe. You want to pay close attention to the polarity markings on this part. In most cases the negative (-) side is marked on the[...]

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MX10 Page 18 ❒ 101. W ow, it’s ha rd to believe we have come 100 steps already ! Install C36, a 10uF ele ctrolytic capacit or. Again check the orientation be fore continuing. ❒ 102. Install C34, a .1uF ceramic capacitor (marked .1 or 104). ❒ 103. Install C8, a .01uF ceramic capacitor (marked 103, 10n or .01). ❒ 104. Install C33, a 220uF e[...]

MX10 Page 19 ❒ 125. Insta ll J6, a 3.5mm mono mi crophone jack . (Identif ied by only three mounting pins instead of five) Note that they do n’t fit exactly in the hole s since a better jack wa s ordered that the one the kit w as originally designed f or. ❒ 126. Install J5, a 3.5mm mono microphone jack. W e have just completed this entire sid[...]

MX10 Page 20 and S4. ❒ 133. Install the next two yellow LEDs (D11 and D23) Check the long lead side! ❒ 134. Install two more y ellow LEDs (D13 and D24). Again check the long lead side. ❒ 135. Install the last of the yellow LEDs to go in the m eter (D14 and D25). There should be two left over for the microphone indica tors. ❒ 136. Install th[...]

MX10 Page 21 ❒ 146. Install R6, the last of the 10K ohm board mount pots. ❒ 147. Install R26, a 10K ohm slider pot entiometer. Notice how the po t only installs easily one direction. Make sure that the leads under this slider and all others are trim med short enough as to not shor t circuit to the bod y of the slider pots. Check to make s ure a[...]

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MX10 Page 23 INITIAL TESTING THE MX10 For this portion of the kit building experience you will need the following items: ❍ Line level source such as a tape deck, signal generator (SG-550) or CD player. ❍ Record level source such as a record pla y er or sig nal gener ator. (Ramsey SG-5 50) ❍ A destination such as an audio amp, transmitter or e[...]

MX10 Page 24 TROUBLESHOO TING GUIDE W ell, w e sincerely hope you get to sk ip this portion of the manual, but this is here to help in the event of an emergency. Remember the detrimental e ffects an incorrectly installed component may have on your circuit. Keep this in mind as you troubleshoot your circui t for possible assembly errors. PROBLEM: No[...]

MX10 Page 25 MODIFYING THE PHONO INPUT This is for those of you who don’t w ant to use the phono input, but would like to have another LINE inp ut. Follow these steps and you will then have anot her line inpu t! Don’t de stroy your parts taki ng them out s ince you ma y want to re- install them later. ❒ 1. Remove R57, a 180 ohm resistor. (bro[...]

MX10 Page 26 P A RTS SIDE VALUES[...]

MX10 Page 27 PARTS SIDE LAYOUT[...]

MX10 Page 28 CONTROL SIDE L A YOUT[...]

MX10 Page 29 USING THE MX10 Above shows a full installation for radi o broadcasting usin g one of the Ramsey micropower transmitters. The parts and pieces a re as follows: ❍ MX10 , our new ly built mixer ❍ STC1 , Stereo transmitter companion. Co mpression, limiting, bass, midrange, and treble controls. Active 8th order lowpass to get rid of int[...]

MX10 Page 30 W e sincerely hope you have enjoyed building this kit. W e invite y ou to check out our catalog and see all of the projects that y o u can put together. W e have one of the most complete line o f kits available today, a nd many more products to come. Giv e us a buzz, well send you a catalog . Call or write: Ra msey El ect ro ni cs 590 [...]

MX10 Page 31 The Ramsey Kit Warra nty Please read carefully BEFORE calling or writing in about your kit. Most problems can be solved wit hout contacting the factor y . Notice that this is not a "f ine print" warranty. W e want you to understand your rights and ours too! All Ramsey kits will work if assembled properly. T he very fact that [...]

MX10 Page 32 PROFESSIONAL STEREO MIXER KIT Quick Referenc e Page Guide Introduction ..................... ............... 4 Circuit Description .......................... .5 MX10 Parts List ..... .................... ...10 Assembly Procedur e ............... ...... 11 Schematic D iagram ...... ................ 16 Initial Testing ...................[...]