Search found 684 matches

by Goldfinger
Sat Jul 15, 2023 12:14 pm
Forum: rx and tx mods
Topic: hifi rx/tx mods for Stryker 497hpc?
Replies: 5
Views: 1383

Re: hifi rx/tx mods for Stryker 497hpc?

As far as a windup, not sure if anyone has come up with one as there is no clarifier. Yes, the echo would have to be bypassed if you want wide audio through the mic jack. If the TX is going to be direct injected you wouldn't need to. Bypassing the echo can be accomplished by unhooking the Mic I/P fr...
by Goldfinger
Sat Jul 08, 2023 8:54 am
Forum: rx and tx mods
Topic: VFO wind up for Stryker 955?
Replies: 9
Views: 2502

Re: VFO wind up for Stryker 955?

I think D-rail designed a little wind-up circuit for the Stryker. (He is a sharp guy) One can be constructed for any radio with a varactor that doesn't/can't have isolated TX/RX clarifier feeds. It would have to be custom tailored for each chassis and is beyond the scope of the average experimenter....
by Goldfinger
Mon Jul 03, 2023 3:10 pm
Forum: rx and tx mods
Topic: VFO wind up for Stryker 955?
Replies: 9
Views: 2502

Re: VFO wind up for Stryker 955?

The D-rail $1600 wind-up mod? :lol: :roll:
by Goldfinger
Sun Jun 25, 2023 1:31 pm
Forum: rx and tx mods
Topic: Vfo wind up
Replies: 35
Views: 14246

Re: Vfo wind up

If it's gonna work on the 2547 you would use a 470 or 1000uF, 16V with the + going to the center leg of VR7 (on the front edge of the main PC board) and the - to board ground.
by Goldfinger
Wed Jun 07, 2023 11:31 am
Forum: Microphones & Mic Wiring
Topic: turner plus 3 cap help
Replies: 2
Views: 331

Re: turner plus 3 cap help

by Goldfinger
Sun May 28, 2023 8:24 am
Forum: >>> HIGH FIDELITY AUDIO Q and A <<< POST QUESTIONS AND COMMENTS HERE!
Topic: President Madison 858pll First Gen DIRECT INJECTION
Replies: 2
Views: 204

Re: President Madison 858pll First Gen DIRECT INJECTION

I've posted the hifi info for that chassis per a previous request but the 858 sideband chassis is not a good choice to hifi. This is because it uses a modulation transformer that can't pass low frequencies. Direct modulated radios like the 148/Grant XL/2000 or Galaxy/Ranger are better choices.
by Goldfinger
Wed Mar 01, 2023 11:21 am
Forum: rx and tx mods
Topic: Request - Stryker 955 cap mods
Replies: 26
Views: 7452

Re: Request - Stryker 955 cap mods

C542 is also on the feedback circuit of the U500A/U500B team. Both sections aren't there for gain, they are set up for roughly unity gain and are strictly for tone shaping. Most of the mic amp voltage gain is in the earlier stages which are wired for flat response, limited only on the low end by the...
by Goldfinger
Tue Feb 28, 2023 9:30 pm
Forum: rx and tx mods
Topic: Request - Stryker 955 cap mods
Replies: 26
Views: 7452

Re: Request - Stryker 955 cap mods

For TX looks like you can make the value of C569 lower.
Try removing C501 to change the feedback circuit of the last mic preamp U500B
by Goldfinger
Tue Feb 28, 2023 12:31 pm
Forum: rx and tx mods
Topic: Uniden HR-2510 RX/TX, hi-fi mods
Replies: 8
Views: 5879

Re: Uniden HR-2510 RX/TX, hi-fi mods

With the values in the mod above, since none of the high frequency shunt caps are changed the high end is the same as stock which rolls off about 3.5K-4Khz. On the low end with 1uF caps, it starts rolling off at 60Hz and 3db Down at 45Hz. With a 2.2uF it starts rolling off at 45Hz and is 3db down at...
by Goldfinger
Tue Feb 14, 2023 9:47 am
Forum: rx and tx mods
Topic: Anytone 5555n II
Replies: 2
Views: 275

Re: Anytone 5555n II

Lemme know if you find a schematic..
by Goldfinger
Fri Jan 27, 2023 10:36 am
Forum: rx and tx mods
Topic: rci 2970n2
Replies: 14
Views: 4152

Re: rci 2970n2

Yes, for the hifi conversion, the uF value is whats important not the style of cap. SMT would be better as it will solder in more securely than grafting in a discrete component.
by Goldfinger
Wed Dec 21, 2022 12:37 pm
Forum: rx and tx mods
Topic: Uniden HR-2510 RX/TX, hi-fi mods
Replies: 8
Views: 5879

Re: Uniden HR-2510 RX/TX, hi-fi mods

If it's gonna work the RIT will have to be stock. Try installing a 470uF, 16V or higher electrolytic with the + to either the anode of D150 or the center swiper of VR-111 and the - to board ground.
Changing the value of the cap will change the length of the swoop. (if it works)
by Goldfinger
Wed Dec 21, 2022 10:01 am
Forum: rx and tx mods
Topic: Vfo wind up
Replies: 35
Views: 14246

Re: Vfo wind up

Unfortunately the TX and RX must be isolated (fixed frequency on TX) to easily install a windup.
by Goldfinger
Sat Dec 17, 2022 12:25 pm
Forum: rx and tx mods
Topic: Vfo wind up
Replies: 35
Views: 14246

Re: Vfo wind up

It's been a long time since I worked on one. Does the clarifier work on transmit?
Looking at the schematic it looks like it does.
by Goldfinger
Thu Jul 14, 2022 10:01 am
Forum: rx and tx mods
Topic: TX Frequency adjust pot on cbs1000
Replies: 6
Views: 460

Re: TX Frequency adjust pot on cbs1000

Not sure but that could be a symptom of low voltage. If the 8 volt TX rail was low it seems like it would affect more parts of the radio. You could put a volt meter on the collector of Q36 and see if it is: A: switching from 0 to 8 volts when you key the mic. B: If it is indeed 8 volts like it's sup...
by Goldfinger
Wed Jul 13, 2022 1:57 pm
Forum: rx and tx mods
Topic: Cobra 29xlr vfo wind up tx and rx audio mods?
Replies: 1
Views: 513

Re: Cobra 29xlr vfo wind up tx and rx audio mods?

Looking at the schematic it looks like a wind-up isn't possible as the delta tune circuit is completely different from later 29s. What "might" work is putting a 100uf , 16 volt with the + going to the base of TR21 and the - going to board ground. RX: Change C29 and C90 to 1uF polyester or ...
by Goldfinger
Wed Jul 13, 2022 1:12 pm
Forum: rx and tx mods
Topic: TX Frequency adjust pot on cbs1000
Replies: 6
Views: 460

Re: TX Frequency adjust pot on cbs1000

IC4 is the main 8 volt regulator. Q35 is the switching transistor that is controlled by the TX-Out of the main CPU. Q35 controls Q34 the 8 volt RX source and Q36 the 8 volt TX source. CBS1000 TX Switch Schematic.jpg I couldn't find IC4 or Q34 on the CBTricks board view but I did find Q35 and Q36 CBS...
by Goldfinger
Sat May 07, 2022 4:59 pm
Forum: rx and tx mods
Topic: TX Frequency adjust pot on cbs1000
Replies: 6
Views: 460

Re: TX Frequency adjust pot on cbs1000

RV50 (RV5 on this pic) on the front board is the only clarifier adjuster. You sure that isn't the transmit adjuster? On the schematic it's fed by the 8V TX source.
Cherokee CBS1000 swoop.jpg
Cherokee CBS1000 swoop.jpg (86.64 KiB) Viewed 458 times
by Goldfinger
Wed Apr 27, 2022 9:00 pm
Forum: rx and tx mods
Topic: Hifi transmitting
Replies: 3
Views: 838

Re: Hifi transmitting

Finding one that's the same input and output impedance as the original would be difficult at best. As far as frequency response you could just inject one and try it. If low bass makes the audio choppy, just roll it off higher. I've injected a Tram D-201 and it handled bass down to 30Hz. Never tried ...
by Goldfinger
Wed Apr 27, 2022 8:50 pm
Forum: rx and tx mods
Topic: yeasu ft-450D
Replies: 1
Views: 245

Re: yeasu ft-450D

Gimme a couple days to stare at the service manual.
by Goldfinger
Sat Apr 23, 2022 8:47 am
Forum: rx and tx mods
Topic: Hifi transmitting
Replies: 3
Views: 838

Re: Hifi transmitting

You would inject through a .47uF. 250 volt to the grid end of:
C53 on the Mark 3
C220 on the Mark 4a

It can transmit semi-wide, limited on the low end by insufficient audio transformer core area.
by Goldfinger
Sat Apr 23, 2022 8:36 am
Forum: rx and tx mods
Topic: Cobra 29xlr mosfet mod
Replies: 1
Views: 353

Re: Cobra 29xlr mosfet mod

I'm sure it can be done but I don't think CBTricks ever had any instructions for the XLR radios and I've never seen any threads on CB forums either.
by Goldfinger
Sun Apr 10, 2022 12:31 pm
Forum: rx and tx mods
Topic: HiFI mod for Realistic TRC-452
Replies: 0
Views: 449

HiFI mod for Realistic TRC-452

Receive: Change C224, 229, 232 to a 2.2uF 16V or higher Electrolytic, observe polarity TX: Change C277 to a 2.2uF 16V or higher Electrolytic, observe polarity Change C278 to a 1uF, 16V or higher polyester, mylar of non-polarized electrolytic Change C282 to a 2.2uF 16V or higher Electrolytic, observ...
by Goldfinger
Sat Apr 09, 2022 8:30 am
Forum: rx and tx mods
Topic: Vfo wind up
Replies: 35
Views: 14246

Re: Vfo wind up

Great, at least we now know the mod is sound and the clarifier area on the CBTricks schematics are not correct. Chalk up another schematic anomaly to the many I've found over the years on Galaxy schematics...
Thanks for the info!
by Goldfinger
Fri Apr 01, 2022 8:31 am
Forum: rx and tx mods
Topic: AR3500
Replies: 13
Views: 642

Re: AR3500

I hifi'd one back in 2009 for a buddy. He didn't use rack gear so I just did the receive and TX through the mic jack. Sounded pretty deep with a 636 mic.
by Goldfinger
Fri Mar 25, 2022 9:02 am
Forum: rx and tx mods
Topic: Vfo wind up
Replies: 35
Views: 14246

Re: Vfo wind up

I have a lot going on for the next few weeks but I'll look up some of those odd-named radios and see what kind of info there is.
by Goldfinger
Fri Mar 25, 2022 9:00 am
Forum: rx and tx mods
Topic: Vfo wind up
Replies: 35
Views: 14246

Re: Vfo wind up

Yes, many radios are just rebranded Galaxy/Ranger radios (not these necessarily as Anytone are basically Galaxy tech but have more changes than other clones) . As such many of the hifi mods can just be extrapolated. One easy way to see which radio they are clones of is to see what part number the tw...
by Goldfinger
Thu Mar 24, 2022 3:08 pm
Forum: rx and tx mods
Topic: Vfo wind up
Replies: 35
Views: 14246

Re: Vfo wind up

It's hard to tell because the schematic for the 77HML looks incomplete in the clarifier area. The "fine" clarifier pot is not shown and R141 is in the location of D38 on the 55HP schematic. D38 isn't shown on the 77HML schematic so trying to make sense of the CBTricks clarifier mod for the...
by Goldfinger
Wed Mar 09, 2022 10:44 am
Forum: rx and tx mods
Topic: Kenwood TS440s request
Replies: 4
Views: 359

Re: Kenwood TS440s request

The only service manual I can get without paying money or getting malware/virus is a shitty 8.67MB file that's too blurry to interpret. If you have a way to get a cleaner copy, let me know. It's too bad the site manualslib.com decided to have malware on their website, they used to be one of the best...

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