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timrim

The radio has no transmit. I suspect a mixing issue. There is a good strong 45 mhz signal on the output of the TX mixer IC.
I have a 10.695 signal on the TX mixer. The mixer has been swapped out.

Any ideas?

EDIT: I found bad TR8 receive mixer, the receive is now working

timrim

I have an RCI-2990 that I am trying to repair. I have a complete test bench with everything. The radio has a very high dead key on USB and LSB. The AM works, except the frequency is unstable, like it it out of lock. Also, when I vary the power on AM, the transmit frequency changes. If I remove D-45,...

timrim

Was the original FET a SK45?

timrim

what is the conversion for the new version Stryker sr447hp's?

thank you

timrim

I am looking for a suitable substitution for the following part (channel display): Part number on board: D551 Manufacturer part number: LL-2255SL Uniden part code: BDAY0530001 If no one knows of a suitable substitution, does anyone know the specs on this? Voltage, Current, Dimensions etc? If I had s...

timrim

Hi Zodiac,

Thank you for the reply, do you also have the binary data for the PLL's pins #9 - 17 on CB channel 1?

Thanks
Tim

timrim

I need the truth codes for the galaxy DX 88, if the complete chart is unavailable, please provide the binary truth data for CB channel 1.

Thanks,
Tim

timrim

I found the service manual on cb tricks, so if someone is familiar with the PLL in these, please give me a place to start.

timrim

Radio Make and Model: Browning Golden Eagle Mk-IV PCB Number: N/A PLL Number: MC4044 Phase Detector (IC-109) Test gear available: Complete bench Symptoms: PLL Unlock causing channel display to go blank Intermittent problem What is working: Receiver all the time and transmitter when PLL is locked Wha...

timrim

Radio Make and Model: SS158EDX PCB Number: EPT690010D PLL Number: MC145106P Test gear available: Complete bench Symptoms: Talkback won't turn off even with echo off What is working: everything What has been tried: checked for cold soldering Did it suddenly happen ?: that way when new Anything else t...

timrim

Yes, you can swap crystals. If memory serves me, you can change a mixer crystal in that radio, that will give you a whole new 23 channel group. 23 channel radios are not very wide banded however, so I would not try to go too far.

timrim

The superstar is a nice radio, you wont fry the 2sc1969.

timrim

Never ever jumper the diode connected to the transformer! Butcher shops do that! The diode is there to protect the modulation transformer.

timrim

I am not familiar with RMC, but without a frequency counter or another radio with channels, making a roadmap won't be easy. There are just too many different ways to wire the switch for channels. This of course assumes that the switch mods the PLL. If the switch is actually part of a channel kit wit...

timrim

Well if your radio only keys on the a band, or if you start going up in frequency and the transmit drops out, it could be the VCO. Does the radio receive ok on all bands and channels? If so, than the VCO should be ok, then I would suspect an alignment issue between the TX mixer and output stages.

timrim

Yes, it was fixed. I replaced TR-33 and C-97.

In your case, it sounds like the VCO may need adjustment.

timrim

First check all voltage regulators, if they all are good, then I would take a close look at the mixers or possibly first rf amp and/or protection diodes.
CBTricks has the service manual.

timrim

What are the VCO voltages on channel 1 and 40?

Usually the first thing I do when I suspect a PLL/VCO problem is go through the complete
alignment procedure, making notes of any incorrect readings. CB tricks will have all the info you need for that radio. That will point you in the right direction.

timrim

I am glad you fixed it. I have had so many of those radios come in and they all have the same problems.
Happy new year!

timrim

How about a bit of info on how they work?

timrim

You can mod it, but, if I remember correctly, the PLL board will only give you up to 27.575 or 27.595, not very many.

timrim

check the areas near the PLL/VCO, also pay close attention to any small circuit boards that are mounted perpendicular to the main board, those solder connections always develop problems.

timrim

I have repaired a lot of the 18's, almost all of them have had poor solder connections, I would check that before anything else on that radio.

timrim

I think the final is in self oscillation, look at the output on a scope in receive mode.

timrim

All you will need to do is simply remove all wires, near the external speaker jack, you will find a jumper that this relay went to, you will need to install the PCB jumper back in that spot. The relay is glued down, so gently pry up from board. As for putting it back in, I don't recommend using the ...

timrim

Yes, these will work well in a 29.

timrim

Yes, its possible. You will need to mount it on a heatsink capable of dissapating the heat. It is easier buying a stinger board, that has the heatsink and circuit board included, however, I find the heatsink supplied too thin, so I always add more aluminum.

timrim

Hi Chevin, I know that the forum has a few bugs, but I think its still a great place. I will probably hang around until they take it down, and see if I can help out. I have had great help here already from Rick, Defpom and the others, so I can't just abandon them. I really enjoy it when I am able to...

timrim

I tried to do a search, but i get the following error: SQL Error : 2006 MySQL server has gone away

Does anyone know the conversion for this radio?

timrim

Does anyone have the schematic of the "Key" that plugs into the processor on this radio?
I am very curious as to how they work.

timrim

It should be doing more than 55 on AM, 15-20 watts more at least. Remember that a shop will tune the radio on a dummy load which represents a perfect 50 ohm load and a 1:1 swr, so there is always going to be some difference, but that does seem excessive. Are you sure that your not dropping voltage o...

timrim

I don't think this project is for anyone that does not wish to risk losing big money on the MOSFETs if something goes wrong, I have been doing some research and so far, I have been told the MOSFETs sell for about $165 each. I have a couple of exact price quotes on the way, but unless they are cheape...

timrim

CB20Ws are garbage, I would take the 2312's.

timrim

I am going to research parts and prices, if economical, I will be building one, looks very easy, I am just not sure about cost of parts.

timrim

If c79, c80 and c81 test good, then at this time swap out IC2 and see if symptoms disappear.

timrim

Thanks for the reply Rick, I have some 2SA1282's so I will swap that out to keep things safe.

timrim

Has anyone else discovered that the schematic calls for a 2SD355E for TR31 and a 2SB525 for TR33, but yet the radios actually come with 2SD355E installed in both locations, apparently they had TR33 in backwards with a 2SD355E, and it must have worked, but I simply replaced TR33 with a 2SA473, and it...

timrim

I just found out why the PLL was unlocked, C97 was shorted (10volt cap) Radio now receives, transmit not working, transmit light not working. Voltage on pin 8 of PLL is now 8 OK now for the new voltage readings on the following: TR31 E=7.7 Rx 0volt Tx B=8.3 Rx 0 TX C=8.8 TR32 E=0 B=.8Tx 0Rx C=8.4Rx ...

timrim

0 volts on pin 8, so that means the PLL is unlocked I did not suspect that, because when I got the radio TR 33 was bad and I replaced it, so I assumed the problem had to be in switching...Another lesson learned! Unhooking 1 end of R171 allows the receive light to go out when I press transmit, but no...

timrim

Radio Make and Model: President Jackson PCB Number: PB042 PLL Number: MC145106P Test gear available: Full lab setup Symptoms: No TX and RX Switching What is working: It lights up What has been tried: Tested TR31, TR32, TR33, D59, D61, D66 check ok on ohm meter Pulled and tested R187,R202,R168,R203,R...

timrim

Is the 11Mhz signal at TR-29 clean?

timrim

Check 10.240 signal at PLL, if noise is there, replace the 10.240. If still noisy, replace the PLL chip.

timrim

I would take out c-90 and c-92 and test them.
Is the signal on TP-10 normal?

timrim

They are discontinued, and, if you do find them, they are quite expensive, I would not hesitate going with a mosfet at this time, they work really well.

timrim

Explain please?

timrim

Are the voltages on IC5 normal?
Is the VCO output at TP2 clean?

timrim

Do the DC voltages on IC 4 (Voltage reg) look clean on a scope?

timrim

If you examine the output of IC 5 (TX Mixer) on a scope, does the signal look normal or is it distorted? If you also examine the input and output of IC 6 on a scope (Audio output) does the signal look normal or is it distorted? Do the DC voltages on IC 4 (Voltage reg) look clean on a scope? Given th...

timrim

3 of those will work ok, they may get warm on transmit, but should not be a problem. I suggested double the max expected current just to have a hefty margin for error.

They are rated at 3 amps, so you can pull up to that through them without frying them.

timrim

You would need a monster resistor because the current draw of the radio on transmit may be approx 2 amps. You can run the radio off 15 volts, but if you need to get it down, a better way would be to use 3 diodes in series with the positive lead, the diodes will need a rating of at least double of yo...

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