Cobra 142gtl component location

[Nowurtalkin222]

Hi. Could one of you fine folks help me out with the location of r187 on this board. It's in the clarifier circuit apparently, but I can't seem to locate it. Doesn't seem to be any board layouts available anywhere & it's difficult to see and/or find alot of locations on this board. I've looked as closely as I can around some of the other clarifier components, such as d35/d36, but am not seeing r187. I need to check if it there or not or cut, because someone previously screwed up the clarifier job & I'm trying to straighten it out. I had already found & corrected several mistakes, but I can't find that dang resistor location. It might be well hidden. I'm trying to locate it via the schematic but the way the schematic is drawn, it's still hard to find. Eyesight not that good at this point. Using a lighted magnifier but no luck so far.

Really appreciate some help finding r87 location.

Thanks in advance

I hope replies go direct to my email...

 

[Nowurtalkin222]

Hi. Could one of you fine folks help me out with the location of r187 on this board. It's in the clarifier circuit apparently, but I can't seem to locate it. Doesn't seem to be any board layouts available anywhere & it's difficult to see and/or find alot of locations on this board. I've looked as closely as I can around some of the other clarifier components, such as d35/d36, but am not seeing r187. I need to check if it there or not or cut, because someone previously screwed up the clarifier job & I'm trying to straighten it out. I had already found & corrected several mistakes, but I can't find that dang resistor location. It might be well hidden. I'm trying to locate it via the schematic but the way the schematic is drawn, it's still hard to find. Eyesight not that good at this point. Using a lighted magnifier but no luck so far.

Really appreciate some help finding r87 location.

Thanks in advance

I hope replies go direct to my email...

Aw heck, doesn't anyone have some idea? Does anyone have a Sam's maybe? Or for an 8719 Washington, TR490, or whatever else might use same board? Puh-leeese!

 

[kopcicle]

Doesn't sound familiar (not R187 is it?) , what's the problem?

 

[Handy Andy]

PC-385 board?


R187 STRADDLES two lines, RX and the Clarifier voltage feed - which when the radio switches from RX to TX - the voltage to the Varactor diode will be different - so you need to REMOVE (Lift one leg to take it out of circuit) R187 if you decide to unlock the clarifier.

 

[Nowurtalkin222]

Doesn't sound familiar (not R187 is it?) , what's the problem?

I don't get your reply. I asked for the location of r187 & noted its part of the clarifier circuit. Your reply says "doesn't sound familiar" and files from a stalker radio???

 

[Nowurtalkin222]

PC-385 board?
View attachment 37107

R187 STRADDLES two lines, RX and the Clarifier voltage feed - which when the radio switches from RX to TX - the voltage to the Varactor diode will be different - so you need to REMOVE (Lift one leg to take it out of circuit) R187 if you decide to unlock the clarifier.

With all due respect, I asked for help locating the part location, not what its for. Did I not write my post clearly? I tried to make my question clear, but now 2 replies that do not answer the question. Again, I need the LOCATION of the resistor, please. I explained that and I explained why I needed it........

 

[nomadradio]

Really appreciate some help finding r87 location.

Okay, so you did say "R one eighty seven" farther up your original post.

If you put it all back as originally wired, with both D36 and this resistor in place your transmit frequency will be determined by the setting of the trimmer pot VR3. The clarifier will be active only while receiving. Won't have any effect on the transmit frequency.

The FCC requires the clarifier to be disabled while transmitting. If you only talk to one other sideband station on the channel at a time, this is no big deal. You tune him in to sound natural, and he tunes in your transmit signal with his clarifier.

The trouble begins when a third station listens in. The trimpot in the radio will probably not set your transmit frequency exactly the same as the other station. That third guy will be wondering why each of you is transmitting on a slightly-different frequency. That trimpot setting is never quite accurate enough for everyone to be tuned to the exact, same frequency while transmitting.

Modifying the clarifier to "lock" your transmit frequency to your receive frequency just makes life easier for three-way (or more) conversations. That way everyone can transmit on the same clarifier setting. No need to turn that knob every time a different station keys and talks.

Just a preference. Your choice.

73

 

[Robalo]

This is stalker IX

 

[Robalo]

but am not seeing r187

 

[kopcicle]

The teaberry schematic is a slightly better copy than the 140/142 GTL (Same board)
I was interrupted earlier and yes, you did initially say r187.

Not having a 142 easily accessible I will still help.

It seems from the schematic that r187 shares electrical connection with pin 6 MB3756, R201 from the emitter of TR45, R145, (and rx b+ line for that matter ?! ) on the other end the anode of d35, and the wiper of the clarifier pot .

Barring a reasonable photograph it's the best I can do.

 

[Nowurtalkin222]

Okay, so you did say "R one eighty seven" farther up your original post.

If you put it all back as originally wired, with both D36 and this resistor in place your transmit frequency will be determined by the setting of the trimmer pot VR3. The clarifier will be active only while receiving. Won't have any effect on the transmit frequency.

The FCC requires the clarifier to be disabled while transmitting. If you only talk to one other sideband station on the channel at a time, this is no big deal. You tune him in to sound natural, and he tunes in your transmit signal with his clarifier.

The trouble begins when a third station listens in. The trimpot in the radio will probably not set your transmit frequency exactly the same as the other station. That third guy will be wondering why each of you is transmitting on a slightly-different frequency. That trimpot setting is never quite accurate enough for everyone to be tuned to the exact, same frequency while transmitting.

Modifying the clarifier to "lock" your transmit frequency to your receive frequency just makes life easier for three-way (or more) conversations. That way everyone can transmit on the same clarifier setting. No need to turn that knob every time a different station keys and talks.

Just a preference. Your choice.

73

Nomad, I'm getting very frustrated here. I noted r187 numerous times in my queries. I see now, since you pointed it out, that on my last post, the "corrective" incorrectly posted r87 1 time. But I'm certain I made myself crystal clear on several posts what I wanted, ie, the LOCATION of the r187 resistor. Why am I getting all these "explanations" of what the circuit is & how it works & what it's for & the fcc & whatever...... I ASKED ONLY FOR ONE THING & ONE THING ONLY & THAT IS THE LOCATION OF THE RESISTOR. I CLEARLY STATED THAT I COULDNT FIND IT AND SIMPLY NEEDED THE LOCATION ON THE BOARD. READ MY INITIAL POST & THEN ALL THE REPLIES & TELL ME WHAT I DID WRONG IN COMING HERE AND ASKING MY QUESTION... I WVEN WENT SO FAR AS TO EXPLAIN WHAT I WAS Doing & why I needed the physical location. I also explained that I had looked for it but could not find it & that it might be hidden & that my eyes are not so great anymore but used a lighted magnifier. I do not nerd, nor did I ask for any if the info you guys have sent me. I ONLY need the LOCATION of the resistor. I CAN'T FIND IT ON THE BOARD.

At 1st, nobody would, even reply so I asked again. This has happened to me here b4. I don't get it. It's almost as tho you guys are doing this on purpose or not reading the question carefully.

I'm grateful for any help with what I asked for and I gave gone out of my way to read a few thread questions to see if I can be of any help to others.

I realize that even tho I am very careful to proof read what I'm about to post, due to the issues w/auto-correct, etc & I see there was one such mistake (r87) but everything else looks to have been posted clearly & concisely with plenty of notes to make it clear what I want.

So thanks for responses when there was none at 1st, but please try to answer ONLY what is asked. Especially when the response is listed as a "senior member" et al.

Now I'll go check out the posted links for the teaberry stalkers. If that includes any board layouts, that show the resistor, then accept my apology for not looking the 1st time, as I wasn't aware the stalker had the ssme board. So I'll go look now...

 

[Nowurtalkin222]

This is stalker IX

Ok, I should have clicked on 1st pic the 1st time around. My bad. I just did and I clearly see the resistor location just below the xtal. I assure that's exactly where I expected it to be when I first began searching on the board and I kept looking that entire area over and could not see the resistor not the location mark. Thus I am very surprised to see it in the pic you graciously provided. I can't explain that other that say I am right now making a beeline for the radio to look at that in comparison to the picture. I will be very surprised if all of a sudden, it is there & I was unable to see it b4. I will be right back to report one way or the other...

 

[Nowurtalkin222]

This is stalker IX

This is stalker IX

Ok, I knew it was too good to be true. It's obvious to me the pcb pic you posted is not the same board or even similar. That's why I didn't look the 1st time, cuz I didn't think the stalker was the same. It looks like I see an "adder chip" on your pic, which is not on my board. Here's a pic I just took of my board around the pll section, if I can get it to upload.

 

[Nowurtalkin222]

Ok, I knew it was too good to be true. It's obvious to me the pcb pic you posted is not the same board or even similar. That's why I didn't look the 1st time, cuz I didn't think the stalker was the same. It looks like I see an "adder chip" on your pic, which is not on my board. Here's a pic I just took of my board around the pll section, if I can get it to upload. View attachment 37110

By the way, I wonder what that unmarked resistor is in that plug or wire connection box just s a bit above and kitty corner to where it says the pcb # 385

 

[Nowurtalkin222]

Nomad, I'm getting very frustrated here. I noted r187 numerous times in my queries. I see now, since you pointed it out, that on my last post, the "corrective" incorrectly posted r87 1 time. But I'm certain I made myself crystal clear on several posts what I wanted, ie, the LOCATION of the r187 resistor. Why am I getting all these "explanations" of what the circuit is & how it works & what it's for & the fcc & whatever...... I ASKED ONLY FOR ONE THING & ONE THING ONLY & THAT IS THE LOCATION OF THE RESISTOR. I CLEARLY STATED THAT I COULDNT FIND IT AND SIMPLY NEEDED THE LOCATION ON THE BOARD. READ MY INITIAL POST & THEN ALL THE REPLIES & TELL ME WHAT I DID WRONG IN COMING HERE AND ASKING MY QUESTION... I WVEN WENT SO FAR AS TO EXPLAIN WHAT I WAS Doing & why I needed the physical location. I also explained that I had looked for it but could not find it & that it might be hidden & that my eyes are not so great anymore but used a lighted magnifier. I do not nerd, nor did I ask for any if the info you guys have sent me. I ONLY need the LOCATION of the resistor. I CAN'T FIND IT ON THE BOARD.

At 1st, nobody would, even reply so I asked again. This has happened to me here b4. I don't get it. It's almost as tho you guys are doing this on purpose or not reading the question carefully.

I'm grateful for any help with what I asked for and I gave gone out of my way to read a few thread questions to see if I can be of any help to others.

I realize that even tho I am very careful to proof read what I'm about to post, due to the issues w/auto-correct, etc & I see there was one such mistake (r87) but everything else looks to have been posted clearly & concisely with plenty of notes to make it clear what I want.

So thanks for responses when there was none at 1st, but please try to answer ONLY what is asked. Especially when the response is listed as a "senior member" et al.

Now I'll go check out the posted links for the teaberry stalkers. If that includes any board layouts, that show the resistor, then accept my apology for not looking the 1st time, as I wasn't aware the stalker had the ssme board. So I'll go look now...

You can see d35&36 in my pic, but where the hell is r187