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N8YX
02-07-2014, 10:09 PM
Managed to find a couple of Stoner Pro-40s out in Never-never-land. For those unfamiliar with the rig, it's an SSB-only 11M set with an audio notch filter ("whistlestop") and passive mixer front end - as the Drake 7-lines employed. They're pretty popular with the die-hard collector and command big money.

One of these is likely a parts/project rig - I think the synthesizer microcontroller is bad. Thus, I'm going to design a new one for it.

Here's where the purists will cry:

That radio just begs for additional features - bring the Mic Gain out to a front panel control, do something with selectable AGC time constants and selectable IF RX filters. Fortunately, they're 10.7MHz and I can find a variety of bandwidths...including a roll-your-own "variable" design.

If I have to create a synthesizer computer from scratch it'll offer dual logical channel selectors and a way to use them in split mode for TX/RX. Extended frequency ranges, albeit RX-only with a transmitter lockout. A "busy/free" scan function. Improved power supplies. All this without changing anything to do with the TX signal chain - from oscillators through PA. The front panel will remain untouched except for the addition of some concentric knobs - the ones I have in mind look better than the OEMs.

Currently on the hunt for accessories for the radio - SPK-40, OSC-40, SOC-40 and anything else which goes with it.

11624

N2NH
02-08-2014, 06:30 AM
Stick that baby on 10M and have a ball with Ham purists. What's your radio? A Stoner PRO-40. A WHAT?? ;)

She is a beauty. A bit of overkill on 11M though. I'd think of a crystal filter myself. Maybe a rock with some low-end DSP to deal with static crashes.

W2NAP
02-08-2014, 12:50 PM
no excuses on da bowl.

NY4Q
02-08-2014, 07:35 PM
For some reason, that CB rig reminded me of some lyrics that were posted on USENET back in the 90s. I found them funny. So I present them here for you...


Sang to the tune of The Highwayman Written By M.F. Luder
I was a codeless "ham"
Along the coach roads i did ride
With dual band HT by my side
Many a young maid ran from my tirades,
Many a repeater contact I had made
The League grandfathered me in the spring of o-one
But still I want more, my whinings never done

I was a sailor,
I was born upon the tide
On 14325 did i abide
I sailed a schooner 'round the horn to mexico
I went aloft to furl the Outbacker in a blow
And when the mast broke off,
They said that my signal was killed
But i am living still

I was a damn CBer
Across the South deep and wide
Where shooting skip was my only pride
A place called New Orleans on the Mississippi low
I bought an amp that would let me bellow
They DF'd me by listening for the crackling sound
But i am still around
I'll always be around and around and around...

I'll talk on 10 meters
'Cross the Continental divide
And when i reach the other side,
I'll find a place to rest my Budweiser in a can
Perhaps i may become a highwayman again
Or i may simply be a single jamming pain
But i will remain
And i'll shoot skip again and again and again...

NY4Q
02-08-2014, 07:38 PM
no excuses on da bowl.

That passive mixed can handle da bowl...

N8YX
02-08-2014, 07:57 PM
That passive mixed can handle da bowl...

That radio is SSB only. Da Bowl been flushed by its designer, none other than W6TNS.

NY4Q
02-08-2014, 08:18 PM
That radio is SSB only. Da Bowl been flushed by its designer, none other than W6TNS.

Oh I know, but with that mixer, the mobile super bowl could drive right by your QTH while in a "radio race" and you'd still be able to conversate, methinks.

What's it got DBDR?

N8YX
02-08-2014, 08:39 PM
Oh I know, but with that mixer, the mobile super bowl could drive right by your QTH while in a "radio race" and you'd still be able to conversate, methinks.

What's it got DBDR?
HP hot-carrier diodes in a quad. Not sure of the device numbers. I'm going to do some BDR and close-in IMD testing, and may end up experimenting with a matched quad of 1N5711s if the OEM parts aren't quite up to the job.

No 'bowlers in my immediate area so I don't have that problem to worry about.

NY4Q
02-08-2014, 09:34 PM
HP hot-carrier diodes in a quad. Not sure of the device numbers. I'm going to do some BDR and close-in IMD testing, and may end up experimenting with a matched quad of 1N5711s if the OEM parts aren't quite up to the job.

Yeah, that's gonna be a fun project. That front end sounds bullet proof.

WØTKX
02-08-2014, 10:41 PM
It's so darn Ten Tec looking... ;)

kb2vxa
02-09-2014, 02:01 AM
STONER? If you accidentally let the smoke out stick your head over the radio and breathe deeply. Recycled smoke has its uses. Anyway, if you're going to so much trouble to design a micro for it the rest better be made out of gold. Oh, if you hear lightning crashes on 11 or 10M the storm is too close for comfort.

NY4Q
02-09-2014, 06:25 AM
Speaking of letting the smoke out :

I worked in a radio shop when I was taking electronics courses back when I was a youngster, and one day I was working on something and got a test lead across the MAIN input and it vaporized the lead tip and I had my head stuck right up in there trying to look in the case. WELP, when it arched, I gasped and sucked in that lead (now in a gaseous form) and that like to have choked my ass to death. That was one more nasty hit.

N8YX
02-09-2014, 06:57 AM
It's so darn Ten Tec looking... ;)

I noticed that. Dave, where do you think I could get a few enclosures of the same style?

WØTKX
02-09-2014, 01:29 PM
Hammond, man, Hammond. (http://www.hammondmfg.com/dwg21CWW.htm)

http://www.hammondmfg.com/jpeg2/1444CWW_GrpB.jpg

kb2vxa
02-09-2014, 08:04 PM
Looks like you live up to your call, BBQ! Lead vapor is the kind this guy would smoke, when he wasn't welding galvanized pipe with his breath... <ffffft> like Godzilla... <fffft> ... (hhhh)... it gives off deadly fumes. Long story about my old CB alter egos from back in the daze, here's an air check of the only one recorded. Pardon the holes in the audio, too close to the mic without a pop screen tends to drive a peak limiter into the ground.

We now return control of the thread to you, until next time, when CB takes you to...........The Outer Limits.

N8YX
02-11-2014, 06:17 AM
#367 has arrived and was placed on the bench last evening. 12v power supply is out - parts inbound.

Dave, that's exactly what I'm looking for in the way of cabinets. Now turn the hat trick: Stoner used aluminum extrusions for decoration and to tie the various cabinet sections together. The corner pieces are what's known as double flange while the section between the display and the front control panel is an h-channel. Problem is, they're the ornamental type - instead of the commonly available heavy structural variety.

Know a good source for the decorative version...which will accept a panel of ~16ga thickness?

N8YX
02-14-2014, 06:04 AM
#439 showed up yesterday.

This puppy is going to need some help.

N8YX
02-15-2014, 05:26 AM
#367's receiver is back in operation. Got the 7815 regulators I needed, removed the bad one from the power supply board and replaced with a good part. +5 and +12 now present, but no +9v...and the +20v line was getting dragged down lower than I cared for.

Checking the 9v supply line, I measured 140 ohms to ground at the 7808 regulator. Comparing that reading with a check of #439's board - which did seem to function correctly - shows the circuit connected to the 9v regulator output terminal ought to read ~8k ohms.

It was getting late. A board swap will confirm my suspicions - and it did. After a bit of adjustment to the various oscillators and AGC circuitry I now have a functional radio.

I need to check the oscillators and timebase reference with a frequency counter then verify transmitter performance but I think this one is good to go in the receive department.

A bunch of knobs and crystal filters are inbound for the next phase of this project. #439's destiny will be as a FrankenRadio.

WØTKX
02-15-2014, 01:49 PM
Checking with Google -Fu search term:

metal H channel for panels

H channels are available from a few sources, but usually for large orders. A few "hits" below...

http://www.johnsonrollforming.com/display.php/display/N2/category/33

http://www.brunnerent.com/Tools/Portfolio/frontend/itemlist.asp?type=9&size=0&lngDisplay=0

There are some in plastics (omit the word metal in above search) as well, which might work OK...

http://displayproductsonline.com/extrusions/h-channel/3-mm-h-channel-278.html

Have fun obsessing over all that. ;)

n2ize
02-15-2014, 10:04 PM
I would crank that thang, run it into a 100000 jigapill DAVE MADE amp and get on da bowl wid all em Jigawatts.

N8YX
02-16-2014, 12:40 PM
#367 is fully operational and chugging away as I type this. Had to set the S-meter adjustment, notch filter depth...rewire the mic connector to the 4-pin Ten-Tec standard so I can use one of several on-hand mics with the rig. Carrier balance set, squelch threshold set...internal mic gain set. Puts out a full 12w PEP.

'TNS did a very slick thing when he designed the radio. Channel selection is done by 4 switches - slow up/down and fast up/down. The PTT line is wired in such a way that if any of those switches are depressed, the radio won't transmit.

Of course, it goes without saying that if any of those switch contacts are dirty, the PTT signal won't appear at the mic connector. :wall:

DeOxIt spray is your friend. Really. :agree:

Two hours of the morning were spent running down parts to fix the other radio. Once it's up and running, #439 will become my "test mule" for some modifications I'm planning. It turns out that certain Watkins-Johnson radios use the same IF as this set, and it also turns out that I managed to snag two 2.0KHz, a 3.3KHz and a 6KHz filter from those radios. So...Phase 1 of the selectivity upgrade will consist of the design of a daughterboard which accommodates the stock filter, one of the 2.0KHz filters and the 3.3/6KHz pair. As is done with the Drake TR7, I'll use the stock SSB filter on TX then allow independent RX filter selection via front panel switch.

Phase II might consist of said daughterboard but instead of the two wider filters I'll substitute three of my own design: One of ~2.8KHz, one of 4KHz B/W and the fifth set up as a variable bandwidth or variable center frequency with a fixed 2.4KHz B/W.

There be...possibilities. Lots and lots.

I need to design another front panel board too - the new control layout requires ganging the AF and RF Gain controls, doing the same with the squelch and notch ("whistlestop") functions, incorporating ganged switch/potentiometer assemblies for the AGC/Mic Gain and B/W Selection/VBT controls. Jury is still out on that "Mic Gain" control: It could turn into an RX Tone control when all is said and done.

A number of people have made the observation that the radio drifts. Yes, it does. Specifically, the counter: It's a direct reading type. The timebase is a crystal oscillator which uses a 2.560MHz HC-6/U rock with no temperature compensation scheme. I can design one for it, or I can get clever and build a different reference oscillator using a DDS and a PIC to load the control sequence at power-up. Drift is negligible with such an arrangement and spectral purity isn't much of an issue - the reference is used to drive a TTL divider chain which has a low-pass filter at its output.

I'm also planning to build a separate 5v power supply into the case, as a number of other owners have done. The main supply runs much cooler as a result.

Dave, I'm looking to build another case which matches the appearance of this radio and drop the guts of an SBE LCB-8 into it. The radio has no AM function so a companion AM set might be what the doctor ordered - and in the RX department, the SBE is a pretty decent performer.

As far as


I would crank that thang, run it into a 100000 jigapill DAVE MADE amp and get on da bowl wid all em Jigawatts.

goes, that might be enough to raise Mr. Stoner from his grave and induce his corpse to walk the U.S., find your flat and choke you. :lol:

K7SGJ
02-16-2014, 12:50 PM
#367 is fully operational and chugging away as I type this. Had to set the S-meter adjustment, notch filter depth...rewire the mic connector to the 4-pin Ten-Tec standard so I can use one of several on-hand mics with the rig. Carrier balance set, squelch threshold set...internal mic gain set. Puts out a full 12w PEP.

'TNS did a very slick thing when he designed the radio. Channel selection is done by 4 switches - slow up/down and fast up/down. The PTT line is wired in such a way that if any of those switches are depressed, the radio won't transmit.

Of course, it goes without saying that if any of those switch contacts are dirty, the PTT signal won't appear at the mic connector. :wall:

DeOxIt spray is your friend. Really. :agree:

Two hours of the morning were spent running down parts to fix the other radio. Once it's up and running, #439 will become my "test mule" for some modifications I'm planning. It turns out that certain Watkins-Johnson radios use the same IF as this set, and it also turns out that I managed to snag two 2.0KHz, a 3.3KHz and a 6KHz filter from those radios. So...Phase 1 of the selectivity upgrade will consist of the design of a daughterboard which accommodates the stock filter, one of the 2.0KHz filters and the 3.3/6KHz pair. As is done with the Drake TR7, I'll use the stock SSB filter on TX then allow independent RX filter selection via front panel switch.

Phase II might consist of said daughterboard but instead of the two wider filters I'll substitute three of my own design: One of ~2.8KHz, one of 4KHz B/W and the fifth set up as a variable bandwidth or variable center frequency with a fixed 2.4KHz B/W.

There be...possibilities. Lots and lots.

I need to design another front panel board too - the new control layout requires ganging the AF and RF Gain controls, doing the same with the squelch and notch ("whistlestop") functions, incorporating ganged switch/potentiometer assemblies for the AGC/Mic Gain and B/W Selection/VBT controls. Jury is still out on that "Mic Gain" control: It could turn into an RX Tone control when all is said and done.

A number of people have made the observation that the radio drifts. Yes, it does. Specifically, the counter: It's a direct reading type. The timebase is a crystal oscillator which uses a 2.560MHz HC-6/U rock with no temperature compensation scheme. I can design one for it, or I can get clever and build a different reference oscillator using a DDS and a PIC to load the control sequence at power-up. Drift is negligible with such an arrangement and spectral purity isn't much of an issue - the reference is used to drive a TTL divider chain which has a low-pass filter at its output.

I'm also planning to build a separate 5v power supply into the case, as a number of other owners have done. The main supply runs much cooler as a result.

Dave, I'm looking to build another case which matches the appearance of this radio and drop the guts of an SBE LCB-8 into it. The radio has no AM function so a companion AM set might be what the doctor ordered - and in the RX department, the SBE is a pretty decent performer.

As far as



goes, that might be enough to raise Mr. Stoner from his grave and induce his corpse to walk the U.S., find your flat and choke you. :lol:

Weekend at Stoners'?

N8YX
02-16-2014, 02:16 PM
Weekend at Stoners'?
Nope; the in-law's.

I always cry at weddings. Especially if they're too long.

Last part of this phase of the project is finished: I connected up a CPI CP-400 to the Pro-40 via the "CB-AM" connector. The CP-400 uses the same mainboards as the vaunted CP-2000; in fact, a '2000 is in essence a '400 with a few more controls and another meter brought out to the front panel. So...I can perform A/B tests between the receivers.

Early results: With the Pro-40 set up as per the 'Performance Checkout' section of the owner's manual, let's just say that - apart from the neat functions like an onboard audio notch/peak filter - Stoner Owners might be a mite bit disappointed, given the radio's reputation. The neighborhood lidiot with the peaked-out export radio still clobbers any receiver I put online including my commercial stuff. I had hopes for the Pro-40 in that I could monitor CH38 with the squelch set to minimum and not have Bozo trip it open with a bunch of splatter.

WØTKX
02-16-2014, 02:18 PM
That crap clobbers my Flex, Ten Tecs, and Kenwood. Whatchoo gonna do? :irked:

N8YX
02-16-2014, 03:31 PM
That crap clobbers my Flex, Ten Tecs, and Kenwood. Whatchoo gonna do? :irked:
Well...I had to try all the avenues at my disposal before capturing a trace of the guy's station on my spectrum analyzer then sending it off to the FCC with a note about who and what is causing the problem.

I can hook any number of legal 4w CB rigs up to one of my verticals, hook the Stoner, the CPI or a Drake R7...a Mackay Marine 3031A or (insert_favorite_high-end_RX_here) up to the other, transmit several channels away and simply not hear myself.

The neighborhood splatterbox, on the other hand, could be heard all the way into 10M on occasion from its normal CH32 hangout. I thought we (area hams) had solved this problem once but evidently the at-fault P-O-S Ranger 29xx product was merely sold or traded to someone else instead of being put on the bench and fixed.

N8YX
02-16-2014, 07:03 PM
Pic of the finished (for now) project:

11691

N8YX
03-01-2014, 09:24 AM
If anyone is interested, here's another Stoner from the outfit which sold #367 to me:

http://www.ebay.com/itm/Stoner-PRO-40-SSB-VERY-SCACE-CB-BASE-RADIO-C-MY-OTHER-HAM-CB-HEAR-/181334718035?pt=US_CB_Radios&hash=item2a38643653

Note the blank display - all the actual counter digits are out. The illuminated digits are hardwired, so we can infer the +20, +12 and +5v supplies are working. That leaves the +2v supply for the counter displays and possibly the +9v supply for the balance of the radio. Next to the "H" on the display - which is normally a "-" if the radio isn't being run in 'export' mode - is the decimal point for the PLL out of lock indicator.

The worst thing that could be wrong with the radio is a bad microcontroller - a custom-programmed 'Nitron' chip. I know of a source for them. My SWAG leans toward the latter two supplies being out.

Not a bad deal for an apparently easy fix and the radio looks to be in nice enough cosmetic shape to warrant its purchase.

I'm looking into ways to address the ~1.5KHz drift of the reference oscillator which occurs from the point of power-on until everything comes up to operating temperature.

WØTKX
03-01-2014, 02:49 PM
Must... fight... urges... don't need another... GASP... rayyyydiiiio!

K7SGJ
03-01-2014, 03:23 PM
Must... fight... urges... don't need another... GASP... rayyyydiiiio!

You know you want it..........you must give in.........place your bid........and make it a high one.

n6hcm
03-01-2014, 11:58 PM
i wonder if pat has any cb radios in his collection ...

W2NAP
03-02-2014, 12:27 AM
Pic of the finished (for now) project:

11691


You got to get a youtube account and make some vids man. really you should.

N8YX
03-02-2014, 11:39 AM
i wonder if pat has any cb radios in his collection ...

Good question. Over the years, there were a lot of noteworthy models produced - and many used the same mainboard. The Cobra 148/2000GTL is a prime example. An older Popular Electronics review cited the '2000 as having the best adjacent channel rejection of anything on the market at the time. I had an early '148 (same chassis as the 2000 but sans frequency counter) in my car way back when and as good as the receiver was touted to be it would still get clobbered by nearby base rigs.

That fact led me to search out its true competition - not so much frill-wise as receiver-wise. A number of offerings from the era are considered collectible due to innovative design features (scanning or computer control), limited production runs, uniqueness (the Browning Golden Eagles and Demcos being the only true 'twins' in CB-land, for example) or snob appeal.

How many people would shell out $1k for a 40-channel, 4w AM/12w PEP SSB CB radio when < $700 would net you a Yaesu FT-101E with its 100w of VFO-tuned SSB goodness? People did, however - Tram's D201A, the Browning MkIV/IVa, the Stoner and CPI setups. You could easily tie up $1500+ in 1978 dollars in a full line of either of the latter two. Assuming SSB operation was your primary focus, either the Stoner or the CPI setups would run rings around the rest of the CB world in terms of receiver performance.

If Pat's collection criteria ultimately focuses on performance, those two definitely get the nod.

And if I were a smart man, I would take the shack's CP-400 (the mobile version of the CP-2000 base) and slave it to one of my R7s via an ARB-704 or similar interface...just using the CB set for its transmitter. Alas, that's too hard for 'DSG to figure out when we just want to have a quick bike-to-shack chat on 11M. :lol:

N8YX
03-02-2014, 11:49 AM
You got to get a youtube account and make some vids man. really you should.

Well...let's see. I spent 5h of time in #439's power supply yesterday - most of which was spent trying to un-fsck it and return things back to "stock". Got the proper +5, +14 and +20v...so I installed the Exciter and Counter/PLL boards. Power-up, start checking things out - wait, what's that factory smoke escaping for? There is a 10uH molded choke installed from the base of the driver transistor to the anode of the biasing diode. It's overheating. Looking at the circuit, the only two ways this could be happening are if a collector to base short exists (it doesn't) or if the stage has gone into oscillation at or near the self-resonant frequency of the choke.

Needless to say, here's a YouTube of me in my lab during the event:


http://www.youtube.com/watch?v=QnDxPG3KrtA

N8YX
03-09-2014, 10:42 AM
#439 is partially back in operation with donor parts from #496. These include the Counter/PLL and Exciter Boards.

As detailed elsewhere on IoMH, I did something really stupid with the defective S/RF/SWR meter that came with #439 and essentially destroyed the signal/PO section. After a couple failed attempts to adapt a "replacement" unit which was shipped inside #496, I dug into my junk pile yesterday morning and liberated an S/RF meter from an old Royce CB carcass. Even though the movement itself was a drop-in replacement, the meter sweep was left to right - whereas the Stoner version uses a right to left arrangement, albeit set 90 degrees from vertical.

The design was studied and a workaround identified:

The torsion spring was unsoldered from the centering arm, both sides of said arm were flattened and rotated to bring the solder side into position for an alternate sweep arrangement then ~1/8" of the spring was carefully snipped off and the end soldered to the centering arm. The movement was then extracted from the Royce OEM plastic housing and inserted into the Stoner housing, after which the needle was zeroed with the centering arm.

Put the meter assembly back into the radio and test it out...works great.

Any Stoner owners coming across this post who are in need of replacement movements need look no further than a junk Royce 1-619, 1-640/642, 1-624/625 or 1-641. They all used the same type of meter.

It's also possible to mod one of these for the centered-needle "SWR" function.

I took #496's bottom cover with internally mounted speaker and swapped #367's bottom cover for it. Since I don't have one of the SPK40's yet (and am NOT paying the $250+ which many people think they're worth) this will allow me to run the radio without an external speaker for the time being.

One other addition was done: I had previously rewired #367's mic connector to mirror Ten-Tec's connector arrangement (mic audio/gnd/TX/9v on TX). So...I dug up a NOS Astatic 878DM for use with the rig. Since the radio supplies 9v to the mic's internal preamp on transmit, I don't need to use a battery with it - and I can switch the mic over to my Ten-Tec gear if desired.

Right now the mic's amplifier gain is set to provide ~6w PEP with the Pro40's compressor switch off, and this increases to 10-12w PEP with the switch on. Perfect for local ragchews.

kc4umo
03-10-2014, 04:35 AM
Nice thread.
Always good to see someone bring these type of radios back to life. Been a while since I had one of these on the bench. The last one that was on the bench went for 600 bucks on ebay and that was a few years ago.
Great job!

N8YX
03-10-2014, 07:02 AM
Nice thread.
Always good to see someone bring these type of radios back to life. Been a while since I had one of these on the bench. The last one that was on the bench went for 600 bucks on ebay and that was a few years ago.
Great job!
This is going to get a lot better. How about a stabilized synthesizer reference, 4 RX IF bandwidths (front panel selectable), 4 AGC settings (slow/med/fast/off), also front panel selectable...a mic gain control, possibly an IF Gain or RX tone control. Or maybe a variable filter bandwidth control. The front panel will look stock, albeit with concentric controls for the extra functions.

And the coup de grace: One of those cases will end up housing an SBE LCB-8 as the AM section of the deal. It, too, will look "stock". All mods will be reversible and the channel/clock display will mimic the Stoner's:

CH19A-12:00P

The "A" and the "dash" are going to indicate whether or not the rig is tuned to an RC channel, or is on the "normal" 40CH allocation. A "L" and a "H" range will be provided, and the transmitter will be locked out on all of those ranges unless the planned 80/40/20/17/15M transverter is connected and powered on. Similarly, a lockout will exist within the Pro40 itself: Old man Stoner had the synthesizer programmed so that grounding a pin will enable coverage to 27.865. Unless a transverter is connected and activated, it'll only RX on those frequencies once I'm done with it.

kb2vxa
03-10-2014, 09:43 AM
This thread like many in this forum brought back some fond memories including a couple of funny ones. One in particular is the Dumbco Power Mutilator mic preamp that was a 2.5W power amplifier, a 12AX7 dual triode driving a 6AQ5 power pentode. The funny part is why a power amplifier that can't deliver power into a high impedance (50K+) load presented by the first stage of a speech amp designed for a crystal mic? Now we have another POS crapping up the band, it don't mean a thang if ya ain't got that swang (do wa do wa do what?).

OK, CB isn't ALL bad, but it reminds me of a Top 40 AM station of old "where the shits just keep on coming". You guys have the right idea, take the best of the best, make a few improvements, and use them as QRP rigs on 10M where you can tune up the band out of range of those annoying freebanders and renegade truckers.

n2ize
05-29-2014, 06:55 PM
STONER? If you accidentally let the smoke out stick your head over the radio and breathe deeply. Recycled smoke has its uses. Anyway, if you're going to so much trouble to design a micro for it the rest better be made out of gold. Oh, if you hear lightning crashes on 11 or 10M the storm is too close for comfort.

And if you hear them on a Geiger Counter you know the storm is way closer than closer for comfort. ;)

PA5COR
05-30-2014, 08:03 AM
Made a bundle 15 or more yearss back putting in monolithic 10.695 Xfilters into the radio's.
Most I.F's had several cans coupled with a small C replaced one c put in monolithic Xf and do a tweek up, done.
That surely cleaned up reception and channel "bleeding" over.

Still have some of them in a drawer or so, left over from the project.