Reduce rci 69 plus dead key further then radio knob allows

[jpachla]

My issue is. 69 plus dead key at 1watt swings to 12 on pep and 5.5 on avg. feeding into (non hdv)Texas Star 350dx. I get back swing even at 1 watt, with amp on. I’ve read the dead key can be can be reduced even further via internal mod. However I’m getting conflicting suggestions online. My power supply is a 50 amp supply with 40 continuous. Setup only comes close to 35 with a nice solid holler into mic generally reads 20-25 amp on meter and 26 with clamp
Meter

People keep saying bigger linear amp, yet I’m reading the radio
Can be reduced. According to Texas star specs the linear amp should easily take up to 20 watt swings. I don’t need that so it’s not an issue

Grrrr

 

[BayouRadioAmplifier]

I was just using a DX 250 here that had troubles,
after the transistors were changed to HG C2290s.
Oscillation troubles after un-keying. found problem
in the feedback circuit at resistors R9 / R6.
They put too high a value in.

but the RF input resistor attenuation networks change,
in AM, SSB, or if no button is pressed in.
So have the AM or SSB button on.
or try both SSB and AM buttons pressed together.
this lowers the RF input even more.
but with both buttons not pressed in, I have too much drive,
from 3.6 watts from a Cobra 148.

I think this is a screwball design It should have the same input
attenuator network at all times, and just adjust the output
from your radio. that is how I get them "Palomar" type
amplifiers to work, since they have screwball input networks also.
especially the "V" versions with the variable input pot that burns up,

But your problem could be this as in the DX 250 I have here.
the feedback circuit of resistors R6 / R9 and or capacitors C10 / C12.

or maybe in the "screwball" input networks.
maybe a resistor burned out, R4 or R16.

 

[nomadradio]

The problem is the amplifier is meant for a single-final radio. You're hitting it with about double what it's meant for. Any radio that has to be turned down below a one-Watt carrier is just too big.

Simple, cheap fix is to push in the "AM" button. Should drop the gain enough to accomodate a one Watt carrier, maybe even a Watt and a half.

Yeah, the modulated peak power may fall off by ten percent, maybe even fifteen. There's not an S-meter in the world with a pointer thin enough to see that difference on the other end of the conversation.

Bonus: It will probably sound better that way, too.

The other fix for this problem would be to upgrade to a DX500. Should tolerate this radio's drive level a lot better.

73

 

[doffo]

The problem is the amplifier is meant for a single-final radio. You're hitting it with about double what it's meant for. Any radio that has to be turned down below a one-Watt carrier is just too big.

Simple, cheap fix is to push in the "AM" button. Should drop the gain enough to accomodate a one Watt carrier, maybe even a Watt and a half.

Yeah, the modulated peak power may fall off by ten percent, maybe even fifteen. There's not an S-meter in the world with a pointer thin enough to see that difference on the other end of the conversation.

Bonus: It will probably sound better that way, too.

The other fix for this problem would be to upgrade to a DX500. Should tolerate this radio's drive level a lot better.

73

I always read your explanations... Helpful for many here. Thank ya!

 

[jpachla]

Well, I suppose I will swap my mobile and base linear. I’ll move the kl-503 to base which according to their specs will handle the dual final and move the dx350 to mobile running a single final president richard at 1.5 dk

 

[9C1Driver]

They make two versions of the KL503, one with a driver stage and one with out. The RCI 69 base radio is advertised as a 100 watt radio. It will easily overdrive a Texas Star 350 or KL503HD. You need a bigger amp or smaller radio.

Based on how your Texas Star amp is acting Vs your watt meter readings you might need a better/different watt meter.

 

[nomadradio]

You need a bigger amp

Whupsie. Much bigger. My bad. Forgot how large that model's transmit power is.

73