Flex 3000 adding an amplifier

David Kutiej

Is anyone using a Kenwood TL-922A amp. with the Flex 3000? If so how did you hook it up and make it work, set load/band?  Is anyone using any kind of Amp. with the Flex 3000, what kind and again how did you set it up?   THX  David/KE7JHA

John

I am using an old Amp Uk amplifier which has a ptt socket on the back with a foot switch. Simple and easy. The only other connection between the F3K and the amp is the coax. Its works for me as there is no "digital connection" or serial/cat port on the amp.

David Kutiej

Thank you John for the quick response. Now I not really good at all this but if I understand correctly what you are saying is your amp is keyed up using a foot pedal switch rather then keying up with a microphone. I'll have to look at my Kenwood Amp to see if it has this PTT socket.  Do you mind me asking what kind of Amp you are using?  THX     David / KE7JHA

VE6KWA

Heil makes a nice dual circuit foot switch for keying the radio & amp in proper sequence. Works on all amps and keys the radio as well. I've used mine on several radio & amp configurations. Connect the coax & foot switch and go. Protects both the amp and radio.  I also happen to prefer a foot switch for general operating. Money well spent for me.

David Kutiej

Thank you Ken, I'll go by my local AES store and check out the Heil dual circuit foot switch.  I really like and trust Heil, I used the Gold Series Microphone & Pro Headset on my Kenwood TS-2000 and recently got the adapters to use them with the Flix 3000

John

David, Its an old uk Amp model with 2x 3cx800a7 tubes. It was made for a university or such place and a single band. Its now been modified for all bands. The newer amps have all types of connections which can interface with modern radios, but mine is a simple model, no frills. I used a ptt foot switch to key the amp and then use the mic as normal, once I have tuned up on a particular band with a small signal from the rig in cw mode.

Bill -VA3WTB

I have an Amaritron 811. I use the relay input on the amp to the PTT plug on the Flex.

Conrad Roskelley

Hi David, I am using the AMERITRON ALS 600 solid-state no tune amplifier. I just put a amplifier relay in the circuit as described in the manual and install the proper coax cables. This amplifier works extremely well. I turn on the power switch wait for the power supply to energize and as long as I am switched to the right band and matched with my AT AUTO tuner, then I just hit the operate button and it's ready to go. I have had no troubles with it whatsoever.  Because of flex 3000 is managed differently on the ALC there is no adjustment available. It doesn't need one. I've used it for two years without a hiccup. 73 Conrad K7QCZ

David Kutiej

Hello Conrad and thx for the quick response.  I don't have a manual, maybe you can email me a copy of the pages/part I need to use. You can look me up on QRZ. THX.......I'm very glad to hear you've had no problems, not being well versed in Ham operations and a complete computer nerd I'm more afraid of ruining the Flex then anything else.  THX.......David / KE7JHA

Ross - K9COX

You can key the amp directly from the 3000

External Keying LineThis keying line, which can be given a delay, can be used to key an external device such as a linear
power amplifier or transverter. The external keying is provided by a relay closure to ground, with a
rating of 250 VAC, 220 VDC at 2 A and with a 2.5 ms nominal switching time.

David Kutiej

Hello Ross. I'm sorry I don't understand anything you said. I'm 64 yrs old and I'm not very Ham/Electric/Computer savvy...........sorry.     David/KE7JHA

John

David, on the back of the flex 3000 is a socket shown on page 5 of the owner manual, which is shown as number 6 and marked as TX OUT. This socket provides a close circuit on transmit, so you can key an amplifier instead of using a foot switch. One can vary the delay in closing the relay contact inside the flex tranceiver. In other words, there is a relay contact connected to that socket and it will/ can key an amplifier. Keying the mic, will activate the relay and key the amp.

VE6KWA

David, I suppose we should have clarified how you intend to key the radio with your Heil mic ? Thus my foot switch suggestion. If nothing else, as Tim & others often advise...While not necessary, it's  prudent to have some sort of safety or buffer between radio & amp. Especially since simple isolator kits are available for around 10 to $15.00

Larry Williamson

I know this is a bit old but I wanted to bring it back to the top-- I am new to the Flex 3000 and wondering about this TX Out #6 on the back of the 3000.

My goal is the have the amplifier trigger before the transceiver. If the TX OUT has a delay-- Is this not the opposite that we are looking for? If we had a footswitch in the PTT OUT (instant)  and the amp on the TX Out (delay)----Sounds like a hotswitched amp to me.

Any thoughts

Thank You

Larry

John

I use a foot switch on my amp and have never had a problem, but thats not to say my foot waont slip off the foot switch. The tx delay can be set up a bit high sothat you have time to engage the footswitch before the tx kicks in from the f3000, so the amp will be engaged into tx mode, but the f3000 will engage a short while later. However, we all age and our reflexes slow down, so it might be wise to purchase or build a PTT solution for the amp and the f3000. Keying the f3000 ptt, will not engage the f3000 output for x amount of time, but it will engage the amp first, then engage the f3000 and rf output

Larry Williamson

John, thanks for the quick reply, Let's see if I understand you correctly-- you key the amp with the footswitch first (instant) Then you are using the TX OUT (#6) to trigger the radio with a small delay.

Is this correct?

Thank You

Larry

John

Larry, Basically yes. On page 109 it says that on the back port , the output is delayed x amount after the f3000 ptt is enabled. This means that you can engage the amp ptt and the f3000 ppt, but the Rf from the f3000 wont activate until x amount of times ie 1 second later. So you can use one ptt switch to trigger the amp and f3000 ptt then x amount of time later the rf will start. So, its impossible to hot switch.The amp is waiting for rf but that comes x amount of time after the ptt of both the amp and the f3000 is engaged.

Larry Williamson

One more time and than I won't bother you any more John hihi

Are you using a Y on your footswitch (you must be I would think)?

I have been using the duel Heil footswitch BUT last nigh I noticed the amp starting hotswitching. Over the period of about 1 hour of kicking and stomping my foot, I think I got the relays out of kilter inside the switch. That's the reason I though of using another way a triggering the flex.

Thanks for your help-- much appreciated?

73

Larry 

Larry Williamson

Back again I guess----- There's no indication in the description that this Jack will key the flex----- I would hate to ground it out and smell smoke if the rigs interior?---- Maybe I am missing something here??

(6) External Keying Line
This keying line, which can be given a delay, can be used to key an external device such as a
linear power amplifier or transverter. The external keying is provided by a relay closure to
ground, with a
rating of 250 VAC, 220 VDC at 2 A and with a 2.5 ms nominal switching time.

John

Hi, I went out and came back in Larry, I used a foot switch off ebay and I opened it up and there is a spring which can come off the indents which hold it inplace. I just glued the bottom fast so that it cannot more.
It more like a moving spring problem, than the micro switch. If you dnload the circuits you will see what it is.

Larry Williamson

So if I ground the (6) external key line--- will it key the flex?

David Kutiej

Hello Larry, my name is David / KE7JHA.  I too asked this same question about adding an Amp. to the Flex 3000.  I solved all my problems by purchasing an Ameritron ARB-704. It is a external Amp. keying delay and it works great and i've had ZERO problems.  Now I don't know what the Flex 3000 internal elec. will do or not do but I didn't want to take a chance on ruining the Flex and this has certainly work for me and the Kenwood TL-922A Amp. I've been using. I hope this helps and makes it a little easier for you.

Ross - K9COX

You are not keying the Flex, The Flex is keying the amplifier with a pair of contacts on a relay just like shorting the amp key line to ground. If you plug a line into the RCA jack on the amp and short the other end with a switch or a screwdriver the amp will "key". The 3000 will not be harmed because the contacts can handle 250 VAC, 220 VDC at 2 A  which is more than any amp keying line requirements.

Larry Williamson

Thanks for all the information----- All appears to working now.

I hooked the foot switch in to the Flexes PTT jack and connected the amp straight into the (6) External Keying Line.

Then set the delay to 50ms (not sure what the level of this really needs to be)

So far so good.

Regards,

Larry