| Cobra 29GTL, 29LTD, 29LTD classic, 29LTD classic Gold Cut D11. Change R58 (10 ohm) to a 2.2 ohm resister. Adjust L17, L20, L21, L16 {Some Models}, L14 for max RF output. Change stock final to a 2SC1969. Change stock driver to a 2SC1957, {some model use a 2SC2028 rf driver}. Remove it. Change R123 to a 0.47 ohm resistor. Put a jumper across D8 {by audio transformer}. Change C71 to a 33uf 16volt polarized electrolytic capacitor. Put a 47pf disc cap across C57. Put a 47pf disc cap across R55. For a higher dead key place a 100pf disc cap across C62 {by rf driver}. Adjust L17, L20, L121, L16, L14. Some models dead key 8-10 watts swing 40-50PEP. Retune L14, L13, L12 for max forward power (do not adjust the dead key over 5 watts.) MODULATOR: PARTS NEEDED: 1- 220uF (16 to 25 volt) electrolytic capacitor. 1- 100 to 200 Ohm resistor. (1/4 to 1/2 watt) ASSEMBLY: 1. Make sure your radio is peaked out. 2. Unsolder JP36 near final. 3. In JP36 holes, solder the 220uF capacitor. (negative side of cap. faces final) 4. On the solder side of the board, solder the resistor across the 220uF capacitor. You can use different resistor values to get the desired dead-key. |
Cobra 21GTL,21LTD,25GTL,25LTD,25LTD classic Change R76 (3.3k) to a 1K. Change R43 (10 Ohm) to a 2.7 Ohm. Change R108 (1 Ohm) to a .47 Ohm. Re-tune L211, L212, L214 for MFP |
| Cobra 77X Change R264 (1 Ohm) to a .47 Ohm. Re-tune L211, L212,L214 for MFP |
Cobra 78X Change R91 (1 Ohm) to a .47Ohm. Retune L11, L12, L15 for MFP |
| Cobra 18RV, 23 Plus Change R505 (3.3k) to a 1k, Change R310 (2.7Ohm) to a .47Ohm, Retune L305, L306 for MFP |
Cobra 19GTL Remove TR8 & Change R31 (5.6k) to a 1k, Change C134 (330pf NPO) to a 360pf NPO, Change R91 (1 Ohm) to a .47Ohm, Retune l15, L16, L17 for MFP |
| Cobra 21XLR Change R110 (2.2Meg) to a 1 Meg, Change R35 (10 Ohm) to a 2.7 Ohm, Change R33 (4.7Ohm) to a 1Ohm, Retune L15, L12, L11 for MFP |
Cobra 29XLR, 89XLR Change R87 (2.2Meg) to a 1meg, Change R49 (47Ohm) to a 27Ohm, Change R42 (4.7Ohm) to a 1Ohm, Change R43 (2.2Ohm) to a .47Ohm, Retune L15, L12, L11 for MFP |
| Cobra 87GTL, 89GTL, 1000GTL Remove C128 (.47uf) & TR16, Change R132 (1k) to a 470Ohm,Change C61 (220pf-NPO) to a 270pf-NPO, Change R50 (3.9Ohm) to a 1Ohm, Change R47 (1Ohm) to a .47Ohm, Retune L17, L13, L12, L11 for MFP |
Cobra 90LTD Cut D203, Change R320 (5.6Ohm) to a 1Ohm, Change C335 (100pf-NPO) to a 150pf-NPO, retune L304, L305,L306 for MFP |
| Cobra 139XLR Unsolder cathode (banded end) of D21 & D22 and lift out. Add a 4.7k resister across where D21 & D22 were unsoldered. Change R78 (27k) to a 56k, Change R84 (4.7k) to a 2.2k. Change C174 (56pf-MPO) to a 100pf-NPO, Change C173 (180pf) to a 220pf, retune L32, L30, L29, L28 for MFP |
Cobra 140GTL, 142GTL Remove TR32, change R99 (10k) to a 2.2k, Change R94 (10k) to a 2.2k |
| Cobra 148GTL, 2000GTL Remove TR24, Change R126 (10k) to a 2.2k, Change R124 (10k) to a 4.7k, retune L37, L38 for MFP Tune L47, L48, L46, L45, L38 for max RF output |
Galaxy Saturn (EPT360010a & EPT360011b), super Galaxy, DX88hl, Pluto,
II, 33HML, 44V, Grant-DX, Cobra 148GTL-DX Remove TR32, change R174 (10k) to a 2.2k, change R187 (10k) to a 2.2k |
| Teaberry Stalker IX Remove TR31, Change R162 (10k) to a 1k, change resister (10k) next to R129 to a 1k |
Jackson Run a jumper wire from cathode end of D55 to JP38 (I've never done this mod) Více naleznete zde. |
| HR 2510 Mars/President Lincoln Mod Find IC315(UC1201A,UC1170,UC1250a etc) on the synthesizer board PB121BB.Then locate pins 34 and 35 on that chip, these pins are grounded on the HR2510. But on the European models like the President Lincon they are tied high(+5 Vdc). Therefore to get the extended coverage needed these pins should be tied high. This can be done in the following way. On the solder side of the synth board pins 34 & 35 are grounded by the same trace. With a razor blade cut this ground trace. Now find resistor pack RR301. The left pin of this pack is unused and goes to a solder pad. Now connect a small jumper wire between this solder pad and pins 34 & 35 on IC315. Now you should get coverage from 26.000 Mhz to 29.990 Mhz in the following banks: Band A: 28.000 to 28.490 Mhz Band B: 28.500 to 28.900 Mhz Band C: 29.000 to 29.490 Mhz Band D: 29.500 to 29.990 Mhz Band E: 26.000 to 26.490 Mhz Band F: 26.500 to 26.490 Mhz Band G: 26.965 to 27.405 Mhz Band H: 27.000 to 27.490 Mhz Band I: 27.500 to 27.990 Mhz |
Galaxy 44V / 66V Channel Expansion 1) Open up your radio. 2) Find the small circuit board on the left of the radio. 3) Cut the green wire and tape it off. 4) There is an unplugged connector by this board..plug it in. 5) Near the front of the radio there is a connector marked +10K. Reconnect the plug to the board. 6) That's it.! You now have 8 bands of 40 channels. 25.165-28.755 MHz. |
| SuperStar 3900 + 10 KHz Jump Switch 1) Get a SPST switch and mount it in the radio. 2) Find IC 6 & 7 by the PLL chip. You will see J68 and J 69 3) Solder a wire from one side of the switch to J68. 4) Solder a wire from the other side of the switch to J69. 5) That's it. Flip the switch to jump up one channel. Open Clarifier 1) Find D75 and R135 and cut one end of them. 2) On the back of the clarifier knob follow the green wire to the PC board. Cut this wire from the PC board. 3) Now Solder this wire to a constant 8VDC source, like the collector of TR41. 4) Take the yellow wire and cut it from the knob. Tape this wire it is not needed. 5) This should make the radio TX/RX on the same frequency. 10 Meter Mod 1) Find IC7 ny the PLL chip. 2) Get a SPST switch and mount it in the radio. 3) Solder a wire from one side of the switch to Pin #13. 4) Solder a wire from the other side of the switch to Pin #12. 5) That's it. Put the radio on 'Band D' then flip the switch to jump up to 28.300 to 28.500 MHz |