After 40-plus years of running barefoot across the amateur HF bands, I have now at long last gone QRO with 500W. My choice for this upgrade is the above-titled model by RM Italy. After arrival on 2022-04-27, I had a bit of start-up frustration owing to my non-understanding of one poorly named menu option. Once sorted out, it has since served very well.
When placing my order with DX Engineering on 2022-03-08, the website was showing that it would arrive by end-of-month. This on account of being sold out, but with a re-stocking order already in. Then owing to supply-chain delays, those eight units languished on ship at anchor for three extra weeks outside of its US port waiting a chance to unload.
Even so, this was still very much shorter than had I put my name on the list for an Elecraft KPA-500. Which I didn't want in any case because of perferring a single footprint versus an amp separate from its power supply.
So far, and overall, this amp has performed very well. I am thoroughly satisfied with it. Especially as I get good reports on both signal and tone from those ops with whom I have skeds on 160m and 80m: Roy, K6XK in IA; Tom, W9XP in WY; Bob, K1WGM in MA, and also Art, W8XW in Northern MI. From all others, as well, but many it's these ops for whom my previous 85W had been difficult to make out whenever conditions were less than ideal.
These, my long-time on-air friends were very glad of my purchase, indeed. They report on it fairly, I'm sure ... and with no false politeness ... in declaring my signal not only loud, but also clear.
This amp takes almost no drive. My 40-year old Icom IC-745, dialed back to it's minimum setting for RF power, allows me use of the amp only just barely on 30m. To be having less than 200W I must go barefoot at 85W. And although the IC-745 is technically rated at 10-100W, I know from having measured it with an oscilloscope and dummy load as actually putting out just 6-85W. Which, as turns out, is fortunate, else I could not be using the amp on 30m at all.
The amp's user manual states a maximum input of 25W on 10m through 80m, and 40W on 6m and 160m. Yet I can tell you that 500W is obtained well below those maximum inputs, above which the amp will shut down, displaying "Error PWR > 25W" in its display. What the minimum is, I cannot say, as my IC-745 does not dial down all the way to zero.
Happily, the amp has prevented me now several times from accidentally driving it beyond max. I tune my antenna initially always with just only 10W while watching reflected RF on my MFJ-984. When as close to zero as can be seen at 10W, I then dial up to 85W and re-zero the needle for a perfect 1:1 SWR. That has been my habit now for many a year.
Now, however, I'm needing to dial RF power on the rig down to below 25W max on 80m and above, 40W max on 160m. And three times now, I have forgotten to do that. Immediately the amp shut down displaying "Error PWR > 25W". A very good thing. Especially as the amp sits far to my right on the station setup, sometimes outside peripheral vision.
The amp will shut down also on high SWR. This it did to me only once. A very good thing then as well. The circumstance was my having gone down to the lair for an early 6AM sked on a day when I had not gone on-the-air since that same sked the prior day. Thus to my still-fuzzy brain (coffee having not yet kicked in) that there was no need for any adjustments. This while forgetting that I had unplugged the antenna completely because of predicted thunderstorms that failed to arrive. The amp shut down on pretty much the first dit. A good thing indeed.
When I am tuning my antenna with the amp set on standby, still it senses the frequency and self-selects the right band. This is a plus at least insofar as I need not remember to push its band-select button. If turned off and then back on, it will remember the last band selected and go to that after completing its startup diagnostics.
After some use, I have to agree with QST's review in accusing the BLA600's SWR meter as displaying instead reflected power. And so, the seeming anomaly where increasing power from 300W to 500W on shows as an apparent increase of SWR. That's fine by me, though, since always I've tuned my random wire for minimum reflected power on whichever band I'm transmitting.
So yes, dear reader, I confess it is true. This 500W amp feeds a mere random wire. In my defense, however, know that my random wire is 19-strand, 14GA, and 142 meters long. Bent into a huge horizontal triangle at 12 meters elevation, I call it the Giant Coat Hanger. I use it daily for hour-long CW group skeds on 80m and 160m. Participants hail from every point of the compass. A group among which I was the only non-QRO station. On those bands, to improve my antenna would require buying a derelict AM broadcasting station. And as none were conveniently close plus also priced for my budget, going QRO was the best remaining option.
As a 100% CW op, full-QSK is now my chief criteria in all decisions regarding future equipment upgrade. I'm on the list for an Elecraft K4HD, once the waiting list works its way slowly down to my name. I had considered possibly a Flex 6600 for this same reason, but then demured, the OEM being in far-off Austrailia.
Still, even so, I purchased this amp from Italy as it could be got from DX Engineering with almost no wait. Like the Elecraft KPA-500, this one too has solid-state switching. No clacking T/R relay to ever fatigue, no matter how fast might be my CW speed. No clacking relay to be either heard directly or through the earphones...as always happens, and very loudly, whenever my the semi-QSK timing runs out on my ancient IC-745 should I pause in the middle of sending.
A number of my on-air sked friends have persuasively argued now for some time in favor of my obtaining, real, actual, full-QSK in my next rig. This so that, between my own signals, I might hear any new signals as might try to break in. You know, just as when happens during a regular conversation.
I myself was a bit in doubt as to whether I'd be much liking such an effect. But then, as happened, I built up a kit tranceiver: the QCX+ from QRP Labs. I built up as well the matching kit for a 50W Class D amp. And these both featured full-QSK. Which, after some use, it has turned out that I do like. The ability to hear received stations between my own signals has more than once permitted I interrupt my own umpteenth CQ so as to hear a delayed answer to the prior CQ.
Having this happen left me to wonder how many times I myself might accidentally have trod upon the very answer I had been seeking? How many times might my habitual interlude of 15 seconds proven too short? And yet to wait 30 or even just 20 seconds seems to drag out almost forever. Full QSK solves this dillema perfectly. Very nearly does full QSK make CW almost like operating duplex. How great is that?
And best if it should be achieved with solid state switching. Not with any clacking relay, no matter if be muffled with stickum cushions and rated for 100 million cycles. CW is measure in PARIS units, a total of 50 dits or dahs being one word. At 20-plus WPM that's 1,000 or more T/R closures every minute. It will take a long time for that to be adding up to 100,000,000, but still you will get there eventually. I am very soon to retire, and thus enjoy much more time on-the-air. Plus I have made my career in test engineering, twelve years of that in fagigue and durability testing. Everything mechanical breaks eventually. This much I know for absolute certain. I'd rather not be having that worry.any limit at all. So went my thinking in preferring the solid state option.
If you are a CW op, then no matter your speed, you should probably turn this on. Despite the title of this menu option, it has more to do with changing the way the amp senses frequency-input errors. In modes other than CW, the carrier does not switch on and off abruptly. In those other modes, the amp is at its leisure to determine frequency and thus shut down, raising the flag "Error Frequency" if operated out-of-band. In CW mode, however, the amp is confronted with timing issues on having to sample individual dits and dahs.
In the manual, however, it says only to turn on this option for speeds above 25-wpm. And naturally, because of how the option is named Full QSK, whereas my rig (an Icom IC-745) has only semi-QSK, I did not know to be turning that feature on. Because of the name, I mis-believed that the feature had to do instead with such a case as when the T/R (aka PTT) signal patched in via RCA cable between rig and amp would toggle on-and-off so as to allow hearing between every dit and dah while sending. And as I was manually switching T/R via a toggle on the rig, this feature seemed not to apply.
It does, however, and perhaps regardless of speed. In the manual it states to turn it on at 25 wpm and above. And yet, without it turned on, I was getting "Error Frequency" shutdowns at 18-20 wpm even with the PTT line holding solidly in transmit. This regardless of whether I obtained the PTT signal via the RCA jack on my rig, or via relay driven from pin 6 of the IC-745's ACC jack, or via manual toggle switch wired directly to PTT on the amp. So really the feature is not at all about QSK, despite the name. Turn it on for CW at any speed no matter what.
Being myself a 100% CW op, I now just leave it on all the time. And since I've begun doing that, I have no issues at all with this amp. Whether or not the option presents any problem for SSB, I do not know. I doubt that it does, but can't say for sure. I await some reader's feedback on that.
In one on-line review of RM Italy's BLA600 amplifier, a single strident heckler posted a comment fiercely maligning RM Italy for including among its several product lines one series of linear amplifiers listing a frequency range of 25-30MHz, plus also another for 18-30MHz. Product lines which the OEM claims target the amateur 10-17m and 10-12m bands.
Anyone able to count beyond their fingers and toes will recognize immediately that the 27MHz Citizens falls within both of those ranges. Nor do these amplifiers contain 27MHz band-block filters much in the same way as Ford, Chrysler and GM do not sell cars with anti-speeding governors.
But if illegal use is RM Italy's intended market, they have clearly placed themselves poorly in terms of price. Competitor OEMs offer 27MHz amplifiers very much cheaper. An experimental on-line searches using the keywords CB, Amplifier informed me at once of Baojie's BJ-200 and BJ-300 at $140 and $190 respectively. Also of HYS, who offer the TC300 and TW300N both at $199. These are the OEMs who show up on the first page. This as opposed to RM Italy, which did not appear until several pages further in. Like so, at least, when searching for new. If instead searching for used, then on eBay, RM Italy comes up the sooner. Perhaps because the Baojie and HYS don't survive to make it into second-hand sales?
That aside, RM Italy's claim of targing the amateur does not seem completely ficticious since, for a fact, there do exist commercially made, FCC type-accepted, CB-like (channelized) AM/FM, mobile transceivers capable of just only the 10m and 12m bands. Transceivers to which it is entirely legal to couple a power amplifier. As, for instance, the President Lincoln II+ LINK .
Humorously, one might also point out that the Elecraft KPA-500 is wholly illegal in the UK, where maximum power is 400W. Likewise Elecraft's KPA-1500 along with many another brand name and model advertised within the very pages of QST are wholly illegal in Italy, where the limit is 500W. Yet do law-abiding amateurs in either of those countries malign the Elecraft or Ameritron brand names on this account?
As for the model BLA600 specifically, one needs only to know that it is FCC type-accepted. The BLA600 has separate band-filters for all of these: 160m, 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, and 6m. Thus the BLA600 cannot be used on 11m. It will fault out and shut down displaying an error for out-of-band input.