Dx400 bilateral attenuator

[nfsus]

Anyone have a way to add an attenuator to the dx400 to make it a high drive? Yeasu runs under 100 and so does the qt80.

 

[9C1Driver]

Both those radio's have an RF power control, turn the drive down. For SSB use I would start both radio's at 8-10 watts PEP and see what the Max power is out of the Texas Star. Then you can adjust up from there. Probably won't need more then 10-20 watts on SSB. Should sounds great. If you really need to hit something with 70-100 watts PEP you will need a bigger better amplifier.

 

[nfsus]

Both those radio's have an RF power control, turn the drive down. For SSB use I would start both radio's at 8-10 watts PEP and see what the Max power is out of the Texas Star. Then you can adjust up from there. Probably won't need more then 10-20 watts on SSB. Should sounds great. If you really need to hit something with 70-100 watts PEP you will need a bigger better amplifier.

I was thinking of making it moron proof. For those times when I forget. But yeah I can crank it down

 

[brandon7861]

I wonder if these are legit or not

Amazon.com

maybe a 5dB and a 2dB to get a total of 7dB. 7dB turns 100w into 20w while 10dB turns 100w into 10w.

 

[nfsus]

I wonder if these are legit or not

Amazon.com

maybe a 5dB and a 2dB to get a total of 7dB. 7dB turns 100w into 20w while 10dB turns 100w into 10w.

Amazon. What Chinese stuff don’t they have. I’m gonna look at that at work today instead of working.

 

[Captain Kilowatt]

I bought a 10dB attenuator several years ago from Florida RF Labs on Ebay. I installed it on the input of a Larcan television amplifier module that was retuned for use on 6m. The idea was to make it idiot proof due to the amplifiers gain and expen$e. I can hit the amp with 100 watts and only 10 watts actually gets thru to drive it to over a kilowatt. You just need to make sure it is only in the TX path so it does not attenuate your RX.

 

[9C1Driver]

I was thinking of making it moron proof. For those times when I forget. But yeah I can crank it down

I see. Maybe Ranch55 will see this and have a suggestion either way.

 

[Ranch55]

You can add some attenuation on the input signal.......
That is what the variable is on a Texas Star HD350V and a Texas Star HD500V amplifiers.
I have removed the variable a few times and added in it's place a fixed resistance to attenuate the input signal.......

 

[brandon7861]

If you build a resistive attenuator that drops 100w to 20w (7dB), the first resisitor will see about 38.3 watts, the middle resistor sees about 34.2w and the resistor closest to the amp input will see 7.7w. Its gotta go somewhere, right? Hopefully not back to the transmitter.

So that brings me to the DX500v dial-a-watt. When switched in, from the transmitter to the amp input, there is a 75ohm shunt resistor and a 250ohm series pot. If you set that pot to let 10w through (109ohm), there is a decent match at the transmitter according to simsmith, but it shows the power in that 75ohm resistor to be 68w and the power in the pot to be 22w. Not sure how those parts survive that (a 2w pot???), but maybe someone can bring me up to speed on that. Edit: I assume it's not be rated for 100w in lol.