How does the RM-HLA-150 hook up to the Flex 1500?

Richard Bligdon,VE3BLI

I am planning to buy a 1500 and saw a video on YouTube showing a ham using the above amp and I was wondering(this is what the RM HLA-150 manual suggests.)if it hooks up straight or if you have to hook up PTT also.What about 6 meters though,since it only goes to 30 Mhz?

From the videos,I can't get over how amazing little box is.

Richard McClelland, AA5S

I have this combination of equipment in my shack.  If you google for reviews of the HLA-150, you'll find some useful information.  One item that I culled from these reviews is that HLA-150 has reasonably decent spectral performance when using the lower power setting (good for about 50 watts) while the higher power setting produces more than average levels of intermod distortion.  I keep mine on the lower power level and I've never received a negative signal report.  

I have the output of my Flex 1500 hooked directly to the RF input of the HLA-150.  I don't have the PTT connection set up between the two.  I may be hot switching the amp without the PTT connection, but I haven't noticed any detrimental effect from this arrangement.  Band switching on the HLA-150 is not automatic, so you'll need to change bands manually.   6 meters isn't going to happen on an unmodified HLA-150 since the band pass filters only extend to the 10 meter band.

I would prefer to hook up a KPA500 or KXPA100, both of which would do a much better job in the 100 to 150 watt range (when driven by the Flex 1500) but the HLA 150 at 50 watts is a nice improvement over a barefoot Flex 1500.  The HLA 150 tends to have noisy relays and fans but the price is right.  I am not able to spend a lot of time operating at this stage in life, so I'll wait to upgrade the equipment in my station to something better.

Steve Yothment

I use my FLEX-1500 with an RM Italy HVA-300 with good results.  I can get 100W out or more on all bands.  The HVA-300 detects the transmitted signal from the FLEX-1500 and switches over to transmit mode.  It works very well with no PTT connection to the amplifier.  This is my favorite radio configuration for camping because it can all operate off of a 12V deep-cycle battery.  (I use a laptop to control the radio.)

- Steve

Richard Bligdon,VE3BLI

"Band switching on the HLA-150 is not automatic, so you'll need to change bands manually."

According to the manual(just downloaded) switch #2 is: manual/automatic,and the manual suggests leaving it in the AUTO position which takes care of frequency changes.

Or,did I miss something there?

No matter,time I get a 1500 and buy a another Windows computer(my main one is upstairs) to use with it,the amp will have to wait till later.Still,I saw a YouTube video of a UK ham working another further south on 5 watts!

Mind you,I do have this Tiger 200 80-10 m ssb/am amp I picked up once.lol

Steve Yothment

Oh.  Look inside the Tiger 200 HF amp and see if there is any filtering on the output!  Mine has none.  So, if I use it, I add an external BPF to the output.  Otherwise, I don't think it will pass FCC requirements on harmonic output.

(I hold these BPFs all year for the local club station to use on Field Day to reduce interference between stations.)

- Steve

Richard McClelland, AA5S

Richard, I believe you're right about the automatic band switching.  I forgot about that.  I usually set mine manually when I first turn it on then it switches on its own with a few dits after a band change.

Richard Bligdon,VE3BLI

You can get the manual here(if you don't have it): http://www.rmitaly.com/index.php/en/products/amplifier/item/746-hla-150-plus/746-hla-150-plus