SPE2K-FA with 6500

John G3WGV

I've been using an SPE 2K-FA with my 6500 for some time without the CAT interface, just blipping the key to get the amp to "see" band changes. No problem. Yesterday I decided it was high time I sorted out the CAT connection, which works fine, except...

Not only does the amp change bands when the radio changes (good) but the amp also sends power settings to the Flex (bad!). These power settings override any others, either from Smart SDR or my other clients. As soon as any power change is made on, say, Smart SDR, it instantly reverts to the amp's idea of what power it wants.

I know I can adjust the amp to different drive levels but I really don't want the amp telling the radio what power to run at all. I have well developed client solutions for setting the Flex output power. I can't find any way to either stop the amp continuously sending its power setting demands or stop the radio from responding. I tried cutting the RxD line into the radio but that stops everything, so there is obviously some sort of command acknowledgement protocol that required RxD in.

Anyone else come across this and/or found a solution?

73, John, G3WGV

Mark_WS7M

John G3WGV

Thanks Mark, that's very useful input. I take your point, to an extent, that the amp is the driver of exciter power requirements but the fact that it totally overrides all other power settings is a real pain! More so because I have put so much effort into my Flex controller and logging software to manage exciter power so there is no need to use any sort of ALC.

I'm concluding that I need to write the amp CAT port into my logging program and not use the 6500's CAT interface at all. That's not a big deal - I have lots of other serial devices that my logger manages - but I had hoped for an easier win than that.

The SPE 2K-FA is particularly frustrating in that its control interface, which I have already implemented in my logger to facilitate Operate/Standby control, only permits band up/down commands, which makes band control via that port messy/tricky. So I end up with two serial interfaces to the amp!

The joys of DIY software!

73, John

Mark_WS7M

Hi John,

I agree with you.  It would be ideal if SPE gave you the power to turn that power update off with a setting.

It really is pretty easy to send the amp frequency data so doing away with the cat is a good approach as long as you always have that other piece of software running.  

For me this problem goes a little deeper in that when I switch either from one band end to the other or to a different band I need to tune.   Yes the SPE amp has a pretty nice tuner in it and for some time I used that but it cannot handle bands like 30m where things are just not resonant.

Yes I should not try to use non-resonant bands on my antenna but I really don't have a choice as I am antenna limited where I am. So I use an HF Auto tuner which could probably tune a tin can on 80m if I asked it to.

its a good tuner but it takes time and while it is tuning the SWR is high and fluctuates.  If the amp has any power it kicks over into standby mode for protection.  I also do not think personally it is ever a good idea to tune under power.

So my process involves taking the amp offline.  Hitting Tune to let the HF auto tune, then putting the amp back online.

Because of the problem you encountered and this it actually makes a lot of sense to not use CAT and to do all through through some external software, like a logging program.

FRLogger does just that for the Elecraft amp which can require frequency data.  So I might add the same feature for SPE.

It is what we have to live with isn't it?

John G3WGV

Hi Mark,

All good stuff. It would also be good if the Flex software gave the option to ignore the power data from the amp but I doubt that's going to happen any time soon, so we have to do our own thing, right?

I already have the necessary code elsewhere in my logger. It's used to set the band on my Ultrabeam Yagi and it uses the standard ICOM protocol, which the amp can also take, so it's really just a case of adding another serial port and copying that code across. As usual it's all the other supporting stuff that takes the time, like adding the new port/function to the logger's configuration management. It's now on my StarLog to-do list!

Thanks for your help.

73, John.