Cobra142gtl

[Smack32]

Hi all... Question for the group ..
I have a 142gtl that has little to no swing with modulation .. Dead keys about 3 watts.. With modulation it jumps slighy to almost 4 than drops to 3.. 3.5.. With stock mor power mic.. Reciever seems fine it has 2 2SC1969 finals in it.. Witch I replaced with what was there .. I tested the finals checked fine.. Hfe numbers were both in the mi's 20s
Any suggestions as to what to look for. Change replace?
Thank You

 

[Xracerx13]

It should have a 2SC2166 for a driver and then a 2SC1969 as a final.

 

[Smack32]

It should have a 2SC2166 for a driver and then a 2SC1969 as a final.

Hi I checked the cross reference .. They are ba the same.. Both cross to the same replacement part # both 16w outputs..
I remember back in the day using 1306.4 watt. And 1307 16watt.. Maybe this should be 2sc1306 or similar ? Or I'm I thinking wrong about this radio. Couldn't fix d a schematic ..

 

[Xracerx13]

a 2sc1306 would work also as a driver but not a 1969 as a driver.
A 2166 compliments a 1969. As does a 1306 driving a 1307.

 

[Xracerx13]

schematic......
https://cbtricks.org/radios/cobra/142gtl/index.htm

shows a 1306 driving a 1969

 

[Smack32]

a 2sc1306 would work also as a driver but not a 1969 as a driver.
A 2166 compliments a 1969. As does a 1306 driving a 1307.

Ok.. That's what the radio actually came with.. Thought it looked odd.. Bill have to locate a 1306 and try it see if it improves my problem .. Thank you

 

[Smack32]

schematic......
https://cbtricks.org/radios/cobra/142gtl/index.htm

shows a 1306 driving a 1969

Thank.you for this link.

 

[Xracerx13]

good luck locating a 1306. You can even put in a 2sc2078 from a cobra 29 or something although others may not think its a good driver. But it can be used.

 

[Smack32]

good luck locating a 1306. You can even put in a 2sc2078 from a cobra 29 or something although others may not think its a good driver. But it can be used.

I thing my local electronics shop or NTE might still have some stock .. I just got a full set of finals for my tram D62 a couple months ago I'll check with them tomorrow .. But thank you for the tip good to know.. Greatly appreciated

 

[nomadradio]

Umm, has anybody checked alignment? Only takes one misadjusted tuning slug to knock the power down to half or a quarter what it should be. L26,27, 28 and L29 should get peaked with a steady tone into the mike, and the mike gain set for under 4 Watts on the meter. If peaking one of them pushes the meter higher, you back off the mike gain to bring it back down. Too much wattage will "flatten" the peak response of the tuning slug as you turn it.

If it's old enough, the "dead flush with the rim" problem can rear its ugly head. Gotta arrange a sticky about that one. Got tired of describing what happens with the skinny slugs appear to "peak" with the slug dead-flush with the rim of the hole in the can.

Short version, it's bad juju.

73

 

[Smack32]

Thank you alvot your help and suggestions on my 142dtl.. Seemed to correct the problem .. Changed the finals.. Nte 235 and nte 236.. Made a couple adjustments as suggested working gest.. Also had to back down the power supply to 13.8.. Was pushing almost 16.. Thank you all for your help
Greatly appreciated

 

[nomadradio]

Way cool! Always a good thing to hear that it worked out like it's supposed to.

73

 

[Cable Guy]

I'd like to know what numbers you are seeing with those nte's.

 

[Smack32]

I'd like to know what numbers you are seeing with those nte's.

Have it dead keying around 7 .. 18 with modulation on am.. In the process of nof recapping .. I'll retune it when I'm done and see what it does

 

[nomadradio]

I would hold the AM carrier down to 4 Watts. A 7-Watt AM carrier is more like "hot rod" level than cruise level.

73