Linear seems like it is not amazing on AM

[Lkaskel]

Hi Everyone,
Now that I was able to get the Lincoln 2+ working the next thing was a linear test (Texas Star DX 350HD). The radio sounds great on AM without the linear on. When the linear is on the carrier is good but the audio is about 20%. When in USB or LSB the audio and signal are great. I do this test with an SDR about 10 miles away. Any thoughts as to why the AM audio is restricted but SSB is amazing?

Thanks!!

 

[Shadetree Mechanic]

What is your carrier power set at?

 

[Lkaskel]

What is your carrier power set at?

10 watts. I was told by the owner that you could go higher with a HD (high drive) amp. Maybe thats not accurate?

 

[Lkaskel]

10 watts. I was told by the owner that you could go higher with a HD (high drive) amp. Maybe thats not accurate?

Oh my!!! I am reading about this amp and it may not actually be a high drive amp. Is that possible?

 

[Shadetree Mechanic]

In order to get 100% modulation out of the amp, the carrier out needs to be 1/4 of the peak output. My guess is that 2 or 3 watts carrier from the radio is all you need.

 

[dave457]

With the amp on set it at a 40w dead key

 

[dave457]

With the amp on set it at a 40w dead key out of the amp

 

[TIN_CAN]

With the amp on set it at a 40w dead key

Do you insert a whistle? maybe hum or yell? for pep?

 

[1iwilly]

Do you insert a whistle? maybe hum or yell? for pep?

no on the transistor amp just set the dead key once that is established then talk normally while watching the forward motion

 

[Lkaskel]

I hooked up the Lincoln 2 and turned power back to about 3 watts (what it took to trigger the amp) and it now sounds great!!! I did not expect to get a lesson in amps tonight but wow am I glad for all of your input!! It makes great sense and shame on amp builders for using HD when in fact they are not.

 

[9C1Driver]

Yea a 10 watt dead key for a Texas Star 350 is mucho grande too hi. Remember most cb amplifiers have HD stamped on them so they sell better. If you have a decent watt meter what is your dead key out from the amp when wide open? It should be say in the 50-80 watt range. You might want to run the radio closer to a 2 watt dead key input.
Also on AM you should be able to key the amp (or trigger it as you put it) with as little as 1/2 of a watt.

 

[sp5it]

It's not AB class linear amp, so signal quality on AM or SSB is questionable.
Mike

 

[Poohbear7663]

Yea a 10 watt dead key for a Texas Star 350 is mucho grande too hi. Remember most cb amplifiers have HD stamped on them so they sell better. If you have a decent watt meter what is your dead key out from the amp when wide open? It should be say in the 50-80 watt range. You might want to run the radio closer to a 2 watt dead key input.
Also on AM you should be able to key the amp (or trigger it as you put it) with as little as 1/2 of a watt.

Even though they put HD on them, that don't always mean that you can have a high dead key, usually they are referring to the swing. You can have a higher swing on AM than the normal 10-15 watts like a regular cb. If you look up the amp on the Texas Star website, it should let you know what the dead key should be and what your max swing should be. If you keep your dead key down and the swing just under what they say max is, that amp should last you a long time.....