Amp Setup with Flex 5000

[Keyports]

I have read enough that I don't know what I am doing so I figured I would ask the community. I recently acquired a new tube amp and I have read that there should be some kind of delay when using a tube amp. Looking at the Antenna configuration box I have several options using TX 1 - 3. The information in the configuration box is great but it does not tell me which configuration would be best for my circumstance nor does it tell me how to figure out how long of a delay I should have or how to figure out how long that delay should be. I also can't find any information letting me know if the delay is different for different modes.

There is also a "Limit Slew" configuration under the transmit tab and I don't know enough about that option to know if I should enable it or not.

Any help is greatly appreciated.

73
Jack

[ke9ns]

I have a Ten-Tec Titan with (2) 3cx800A7 tubes, that I do nothing special for. Just an RCA from TX1 (red) to my Titan.
If you need just a simple PTT with a delay before transmit, just used TX1 with a delay.
But if your amp needs something special, just open the ANT panel and hit the F1 key. That opens up a help screen

Darrin

[Keyports]

Thanks for the reply. I ended up contacting the amp manufacture to see if they could shed some light on the subject. I probably should have started there first. I have another question I'll post in another thread.

[N0DFF]

With a tube amp, you want the amp to key first, and unkey last so there is no RF hotswitching at the amp's antenna relay.

This is done by keying the amp with the "TX1" RCA jack. BUT, set the delay on "TX3" to around 75ms (others set to 0). Check all 3 TX jacks to "on", but check ONLY the "TX3" delay box. This causes the 5000 to key the amp FIRST, then itself. When you release PTT, the Flex unkeys FIRST, then the amp. By doing this sequence, the amp's internal PTT relay NEVER switches with RF on it. You will not notice this delay, but your amp will! I would highly recommend this setup even with a solid state amp.

Good Luck, & 73

DFF

[N0DFF]

I forgot to mention yesterday that it is also very wise to have an amplifier keying interface between your Flex & the amp. When they were the current product offering from Flex, there was a fair amount of discussion about the external amplifier keying IC being somewhat delicate. An interface, such as the Ameritron ARB-704, is a logical and inexpensive investment..

[ke9ns]

Just for future reference, I believe this is the sequence of events for TX1 Red, TX2 White, TX3 Yellow
(I had mistake in the help about when the Receiver turns back on).


PTT ON:

>>>Flex5000 Receiver turns OFF<<<

RCA TX1 output ON (no delay)
Wait TX1 Delay time
RCA TX2 output ON
Wait TX2 Delay time
RCA TX3 output ON
Wait TX3 Delay time

>>>Flex5000 RF OUTPUT ON <<<



PTT OFF:

>>>Flex5000 RF OUTPUT OFF<<<
>>>Flex5000 Receiver turns ON<<< (BUT you will not hear anything until your AMP unkeys)

Wait TX3 Delay time
RCA TX3 output OFF
Wait TX2 Delay time
RCA TX2 output OFF
Wait TX1 Delay time
RCA TX1 output OFF

So if you do not ENABLE a particular TX output (1,2,3), simply ignore it in the sequence

Darrin
ke9ns

[Keyports]

Thank you Gentlemen for you help with the amp setup. N0DFF thank you for your information that is what I had in the back of my mind but did not know how to get there. I knew that I wanted some way of keying the amp first then the radio. So if I understand what your saying plugging the RCA jack into TX1 will start the amp first then key the radio and the delay should not be enabled. The thing I did not think about is the tail end. So now I have the TX3 delay enabled with a 75ms delay. Darrin, thank you for showing me the order of the sequence. I see that you updated the antenna help, I hope that will help others.

As for the Ameritron ARB-704 keying relay I went with KD9SV's SV-KR solid state Keying Relay.
Thanks again, 73 Jack