usually a mic mixer has enough output but in some instances you need a mic preamp

Either way.If you leave C262 in you can still use the front mic jack or the direct inject. If you remove C262, you can only use direct inject.

Ground goes to board ground.

You want to inject through a 10uF, 25V to the output side of C262.

This thread has the direct injection info for an 858 chassis:

858 sideband chassis hifi

I've never compared them but it is said the new model McKinley is the same/similar to the Uniden 880?980 TX: Change C263, C267 to 4.7uF - 16V (or higher) Change C223 to a 4.7uF - 16V (or higher) Change C226 to a 330uF - 16V (or higher) RX: Change C83 to a 2.2uF - 16V (or higher) Change C402, C403, C...

Yes, in 2014 when I posted this mod I didn't know about the cap change on the modulator circuit yet.

Change C260 to a 330uF, 16V (or greater)
If this cap isn't changed, there will be roll-off below 100hz.

Yes, I think the differences between the 11 and 13 boards are minor and are indeed the same in the areas that count. (TX and RX audio chains) I've modded 148F's but never worked on a TR-296 so I don't know with absolute certainty. I'm pretty sure the early models had the "11" board but the...

Thanks again for adding your real-world findings to the forum.

If I remember correctly when I modified the last 3500, it had the cap but it was an early model with the real fragile circuit board.

C229 is close to the audio chip on the schematic but it's possible it doesn't exist on later revisions because it is redundant. C106 is just before it in the amplification line and is already blocking any DC present from the previous stage.

If it's the Grant with the PC-409 board Direct Inject: Inject through a 10uF 25V electrolytic with the + connecting to the - lead of C99. Leave C99 in if you still want to be able to use the mic jack for TX audio. Change C46 to a 4.7uF 25V (or higher) poly/mylar or non-polarized electrolytic. Change...

I'm responding so I don't forget after the holiday. I'll post this up tomorrow.
Happy Thanksgiving!

Open it up and see which EPT main board is in it. If it has the EPT069610Z, the mods for the DX959 or 2547 will work.

Receive: AM Change C60 to a 1uF poly/mylar or non-polarized electrolytic SSB Change C37 to a .22uF poly/mylar or ceramic disc FM Change C96 to a .22uF poly/mylar or ceramic disc ALL MODES Change C101, C104, C229 to 1uF poly/mylar or non-polarized electrolytic Change C106 to a 2.2uF poly/mylar or no...

Hey RangertechDX, I apologize for never posting up the mod, this was just before my Dad died and I had my hands full.

Hey viper926dave, I'll get this posted up soon!

Here

TX: Change C80 to a 2.2uF, 16V or greater tantalum or electrolytic. Observe polarity. Change C71 to a 1uF poly/mylar or non-polarized electrolytic. Want a little bass-boost in the first mic amp stage? Change C82 to a 3.3uF, 16 volt or greater electrolytic. Observe polarity. Want a little more gain ...

Some members at the Worldwide DX forum have said it's similar to a Galaxy DX-979.

Post is edited. Thanks for bringing it to my attention.

ON the CBTricks schematic for the 2517 it looks like C89 but it's probably C39. (on the board it should be located next to Q16)

Once you verify that, I'll modify the hifi information above. Sorry for any inconvenience..

For anyone else doing this mod, Mr. Lightning informed me that C192 is soldered on the bottom side of the main board where the shielded mic gain cable's center lead and C151 solders through the board.

It's also entirely possible it's not in the radio... lol.

Also, changing it's value may not be needed because it may not need the extra treble after the rest of the conversion. I only include the mods that affect the highs to give the hobbyist more flexibility.

Mr. Lightning brought to my attention that he couldn't find C192 on any of the parts view. I looked everywhere in the SAMS and didn't find it listed either. This happens once in awhile with photofacts. Usually the part IS there on the radio but will be located in a weird place hand soldered in. Here...

That last pic was hiding inside the huge foldout schematic pages...

Another added

I added a 4th pic.

BTW, you can right click each pic and save it to your machine, that way you can see them full size and be able to zoom in.

I don't have a scanner right now but hopefully these pics will help..

Not that I have seen.

RX: Change C132, C99 to 1uF non-polarized change C154 to a 2.2uF non-polarized Change C167 to a 1000uF, 25V electrolytic. Observe Polarity Change C176 to a 1000uF, 25V electrolytic. Observe Polarity TX: Change C152, C154 to 1uF or 2.2uF non-polarized. Since this radio has a mod transformer and I've...

Hey bro, I went and picked up my SAMS, I'll get the full HIFI info up soon!

Though it might be a little cleaner it's the same as the CBTricks scan as in half of the schematic is missing.

I'm supposed to be going over to Sanchez's house to work on his radio in a couple weeks. I can grab my SAMS then because they are stored in his shop.