The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

Rick

Check Q108 Emitter 0.00v Collector 0.00v Base 0.70v in all modes bot in ssb the Collector 0.50v Emitter and Base at 0.00v, also check D111, D112, D117, D118 and IC101 Pins 1,2,3,5,6,7,8,11,12,13,14 should be at 0.00v Pins 8,10 6.80v full squelch pin 4 8.00v pins 9 1nd 10 1.70v no squelch. Hope this ...

Rick

I am looking for a schematic diagram for Maxon Model CGX-0510-N, VHF handheld.

Rick.

Rick

I am looking for a schematic diagram for Maxon Model CGX-0510-N, VHF handheld.

Rick

Rick

Disabling Talkback on board model EPTOSSB50C. Disconnect wire J15 to the left of R197.

Disabling Talkback on Early version DX99V find TR35 mid pin and disconnect the wire.

HD run for ever.

Rick.

Rick

I have helped 5 guys in the passed month to get there radios up and running vir the PM on this forum and not a one has express any form of gratitude, is just to much to say thanks.

Rick.

Rick

I have helped 5 guys in the passed month to get there radios up and running vir the PM on this forum and not a one has express any form of gratitude, is just to much to say thanks.

Rick.

Rick

I have helped 5 guys in the passed month to get there radios up and running vir the PM on this forum and not a one has express any form of gratitude, is just to much to say thanks.

Rick

Rick

I sound like you have lost some volts.
Check the voltage at the PPL pin1 it should be about 8 to 8.5 volts also check Tr36, Tr37 Tr38. Tr41 should read (Base 12.3 to 12.6 V Emitter DC input voltage 13.8 Collector 8.3 to 8.5). Lets us know how you get no.

Rick.

Rick

Any mic cable will do.

Rick.

Rick

It about 1/3 of the way back on the right hand side near the audio IC, the Squelch preset is RV1.

Rick

Rick

Hi Martin,

I do not know if you remember me my handle used to be Moonraker or Unit 148 mobile, do you still see Steve T.

Cheers
Rick.

Rick

It sounds like no output from PLL maybe the VCO is not locked.

Rick.

Rick

You have a problem with the voltage regulator circuit

Rick.

Rick

223 you have a PM.

Rick

Rick

Check the CPU, try pressing the reset, check the the CPU osc, i have had the cap on the input side of the osc go bad (4.00Mhz resonator), if you hold down the reset for about 10 seconds and watch the display you should see the display flicker for a stlit second, if you do you need to take out the CP...

Rick

Try rfparts URL www.rfparts.com about matched pair $80.00

Rick

Rick

Its best to use transistor type TIP42.

TR49 on Mk I and TR51 on Mk II. Replace with TIP42

Rick.

Rick

I think it would be best if you take it to some one who can sort it out. Sorry I can not help any more.

Rick

Rick

What size PSU are you using.

Rick.

Rick

If it is the Channel switch why not just take it apart and give it a clean out, Ask Dave Zodiac he lovers the job, I my self I would just put a new one in.

Rick

Rick

The is TR43 (2SC2312) in the Mk1 and TR44 in Mk2, just check the collector voltage while you are key up (PTT de-pressed), you should have about 5.80 volts in AM/FM/CW and about 13.60 volts in SSB mode. Do not slip with meters prob you could shot the Final out.

Let me know how you get on.

Rick

Rick

Ever time I have had a 29 LTD in for repair with on TX is has been the IC3 TX mixer. I think it would be best to check what is going on around the mixer, check if 10.245MHx is present at pin 4 (IC3) and check if 16Mhz plus this will depend on which channel your are on at pin 1 (IC3), the two frequen...

Rick

Check to see if you have volts at the final if no volts check TR49 on Mk I and TR51 on Mk II. Replace with TIP42 from www.grandata.co.uk

Rick

Rick

If you have removed TR13 and it didn't change anything and you told me that the voltage at TR12 max was 0.64 volts the fault has to be TR12 or TR13. If you have a small head phone the ones you get with a walkman, but it from the center connect of the volume control and ground you should have good au...

Rick

Stock fault IC3 TA7310P.

Rick

Rick

This is usually due to bad electrolytic capacitors, last year I repaired a SBE Console V and changed 18 caps and 6 resistors. There radios are now getting very old. Check caps around the voltage regulator.

Rick

Rick

Remove TR13 or left the collector, and tell if you get the audio back.

Rick

Is the display reading wrong? Or is the radio putting out the wrong frequency? If wrong frequency then you need to see what is going on at the PLL program pins (10 to 17). It could be one of three problems the channel switch or the binary adders or PLL chip. Check the program pins on the PLL with a ...

Rick

The next to try is the PA. Plug extension speaker in to the PA socket switch the radio to the PA mode key the mic and speak there should be some output from the extension speaker, if there is no output the Audio IC4 is duff (and not the beer) just replace it, but if all is ok check with a DVM at the...

Rick

Check IC4 (TA7222AP). Switch the radio on and leave it no for a minute then touch the IC if it is very hot, then replace it as it has gone short.

Rick.

Rick

You need to check the VCO voltage at the test point while changing channel, the voltage should change about 0.02 volt per channel if it does not it is probably the PLL chip, as the PLL is known to fail in the cybernet radios.

Rick

Rick

hi there i have a ranger ar-3500 works 100%on am/fw/cw but on ssb its ok for 5 minutes then it just drops output power an idea? this radio is driving me crazy thanks Apply a two tone test while monitoring the collector of Q27 and adjust VR15 if the voltage stays the same then replace Q27 and try ag...

Rick

Hello to all, can anyone tell me what is the best way to calibrate my ssb frequency on my superstar 3900 i have the plug in frequency counter. when it reads 27.555 every on tells me that i am of frequency.I am confused !can anyone help ? thank's in advance... With the right bit kit, or better still...

Rick

shroom wrote:Has anyone done the ERF mods on any radios other than the Cobras and the Galaxies? I've got a few older Midlands and a Colt SSB I talk on an wonder what other resistors/capacitors would be involved?

Send me a copy of your diagram and I will see what I can do. But I will not promise to do it.

Rick

You can replace 2SB525 with BC636 just turn it round as Emitter and Base differ from the 2SB525 or you can use BD136 I have been using them for years. The BC and BD transistors are obtained at most good electronics shops E.G Grandata www.grandata.co.uk Hope this helps.

Rick.

Rick

Hi needlebender2811,
It sound like you are over driving to hi modulation, You should set the mic gain so that only a few segments of indication on the ALC meter. Also the max output on AM must be below 25 watts to get good modulation. Hope this helps.

Rick.

Rick

Wanted datasheet or any infor on SL6691C Chip or pin out would do.

Rick

If your 730 is a late one look on the RF UNIT and cut a small (brown) wire, you should get full TX all bands.

Rick

Rick

This may help some of you in fitting ERF-2030.

Rick

Rick

Anyone help with schematic for old SBE Keycom 1000.

Thanks
Rick

Search found 1040 matches