NEW RM Italy BLA 703 Base Amplifier

[Shockwave]

The original "batch" which was released back around February of this year, and was only sold to European and other countries AND continents where (of course) FCC approval is NOT required.

The latest "batch" which just arrived in America on November 1st, is in fact, FCC approved., and required many months and many $$$$ to make it so...

I've been friends with, and telephoned with (on MANY occasions since 2010) both the lead-engineer (who is British) and the owner (Italian of course) of the RM Italy facility (founded by his father)., and if you had taken the time to even lightly peruse / read the article-links provided in this thread so far., you would have seen that I was just at their facility for the "complete tour"., last month on October 23rd

The amplifier that I display in my articles, was sent directly to me by the RM facility (about 4 months ago) and was (of course) part of their 1st batch for the European / world-wide market, and therefore (of course) does NOT display an FCC number on its back-side.

Now you've switched the subject to comparing a factory-manufactured, "turn-key", automatic band-switching, 1.4 Mhz to 54 Mhz, all-mode linear amplifier (ie: the BLA-600)., with that of something which would be part factory and part hobby-craft...

I never said the RM-3 was a part number, and actually went out-of-my-way (again, if you would have taken the short time to peruse / read the attached / linked articles I had written)., and would have seen where I explained that the RM-3 MOSFETs are "scrubbed" of their actual part number AND as to why they are

I also explained as to why just a few of their amplifiers (less than 10%) utilize the MUCH less expensive, TO-220 case-style MOSFETs instead of VERY expensive / actual RF-devices., which ARE utilized in the other 90% of their amplifiers.

Again., this new 2nd batch, which just arrived in America on November 1st., is in fact FCC type-accepted, and do in fact have the appropriate "FCC ID number" affixed to them.

One must just have the time and patience to read AND humility to investigate a matter-of-concern BEFORE passing judgement...

BTW: Did ya even take the time to peruse / read the attached PDF file of the owner's manual, which supplies at least three illustrations (of which most other commercially built amplifiers do not) and covers the subjects concerning the following:

1: Linearity (power in versus power out) on page #8
2: Frequency versus input to output gain also on page #8
(and its frequency restrictions, unless modified)
3: The harmonic output graph on page #9
(which displays a basic / average "delta" of 70dB.!!

Hell., even on page #10, it explains how to interpret the front-panel bar-graphs, which displays both PEP power and SWR., and both in "real-time".!

++++++++++++++++++++++++++

As my "profile-signature" states...

One of my biggest 'pet-peeves' in life., are those folks with an attitude that's basically saying...
"Hey look man, I've already got my mind made-up, so PLEASE don't confuse me with the facts".!

++++++++++++++++++++++++++

Regards / 73
Eric Klein
Klein Communications
Also as KY8E

PS: I do NOT sell them (RM amplifiers) or Sirio antennas (which I also spent half-a-day at their facilities the next day) or radios, or even microphones. Ever since 1980, when I started my Motorola-only, commercial 2-way radio communications, one-man-show business (over 200 customers and over 3,000 radios), it has always been about absorbing electronics knowledge, schematics, trouble-shooting, repairing, etc., and then doing my absolute best to explain / educate such things in "layman-terms", whether complex or mundane to others, with the goal of keeping other Folks from spending their hard-earned $$$ on "urban-legends" and / or "slick salesman" :-(

Eric, I took the time to investigate everything available on this topic before posting. Including going to the FCC website and see if any certification number had been issued for the BLA-703. I can't find anything listed anywhere for that model number. Can you provide it? On the other hand, I have no problem finding the FCC Certification Number for the BLA-600.

I wasn't changing the subject. I was simply pointing out that separate band input networks are not required on broadband solid state amplifiers. Also, that the necessary harmonic filters for the output section, cost under $150 to add, for all HF bands, plus 6 meters.

With respect to the RM-3, there are very few linear rated RF transistors in this package. The ones that are rated for this application, are highly advertised as such. In the absence of a semiconductor manufacturer's data sheet, it is very difficult to believe that this transistor could possibly be rated for linear RF service.

The only amplifiers that RM Italy manufactures with true linear rated RF devices, carry an FCC ID number and are very expensive. They use Freescale devices at higher voltages in order to meet difficult IMD specifications. They also brag about and publish the actual part number.

I have an extensive background in RF engineering and have worked for every company from Motorola to Microphase, before selling my own business and retiring 3 years ago. Sirio custom manufactured a line of antennas for my business, for 20 years.

I know it's easy to remove a harmonic with as little as two additional parts. I know it's impossible to achieve decent IMD specifications with inexpensive switch mode transistors, operating on 12 volts. That's why the real transistor number is not published and we see nothing related to an IMD specification on this amplifier.

Like you, I am interested in supplying the Layman with accurate information. In this case, it requires the specific FCC ID number for this amplifier, and if the manufacturer is claiming the "RM-3" is a real RF rated transistor designed for linear service, they absolutely need to publish the actual part number with a reliable manufacturer's data sheet.

I recognize I sometimes come off with a lousy attitude and apologize for that. In this case, I'm just looking for the meat and potatoes, to see if they line up with what's being advertised. It just appears to me that RM is advertising a little more than they are selling and they don't need to because they are selling plenty for this price.

 

[smallsandwitches]

The BLA keeps shutting down in SSB and beeps that I'm out of the band when I am on ten meters. I've used two different transmitters, the same result, shut down.

 

[BC Coyote]

The BLA keeps shutting down in SSB

Likely you are overdriving it in SSB. Or it is not getting sufficient volts/amps.

beeps that I'm out of the band when I am on ten meters

From page 1 of this thread, it seems it comes with 10 and 11 meters locked out.
Have you done the conversion to enable it to operate on 10 and 11?

 

[AudioShockwav]

From page 1 of this thread, it seems it comes with 10 and 11 meters locked out.
Have you done the conversion to enable it to operate on 10 and 11?

Post number 11 on first page has two mods, one to open ten and 11 meters, and one that defeats (somewhat) the protection that detects excessive harmonic content in the signal and shuts down.
It's ironic that the RM engineers call this AM for American Mode because American operators (11 meters) have peaked and tweaked radios that trigger the protection.

73
Jeff

 

[Radioman56]

The BLA keeps shutting down in SSB and beeps that I'm out of the band when I am on ten meters. I've used two different transmitters, the same result, shut down.

The BLA-703 "straight out of the box" is designed to operate within the entire 10-meter band, and only needs the 11-meter band modification (ie: R60 removed) for those who wish to operate it in the 11-meter band and / or the upper and lower 11-meter "free-bands".

If you are getting the "4-beep" shut-down warning, then (as the manual states all of the 6 protection-modes on page #9 of the included user-manual) your transceiver is allowing some amount (as small as it may be) of 2nd harmonics (above 30Mhz, or sub-harmonics below 25Mhz) to get into the amplifier's input detection circuitry.

If that's the case (ie: getting the 4-beep" warning) then follow the instructions contained in the 2nd half of the "11-meter conversion" article (web-link below).



It explains in detail., just what causes the 4-beep fault, and how to easily make the "firmware-change" from the amplifier's front panel (nick-named the "AM" mode) to help in minimizing the problem, which is helped by changing the amount of "consecutive-faults" (ie: to 25 detections) over a period of about 1.5 seconds.

If once the firmware change has been made., which is denoted by the AC power-up cycle beeping the Morse-code letters A and M (ie: dit-dah, dah-dah), and you're still having problems., then simply add some type of quality, inline, 30Mhz harmonic-filter box (between your transceiver and amp) to filter-out any possible "dirtiness" of your transceiver, as the BLA-703 is quite sensitive to such frequencies, and is why all the new versions RM produced (and American sold after November 1st of 2024) has the "user-ability" to make the firmware change if / when needed.

Regards / 73
Eric Klein
Klein Communications
Also as KY8E

PS: If you can't get the AC power-up beep to change from the single / long beep, to the dit-dah, dah-dah Morse-code beep., then your BLA703 is from the earlier edition, which were being sold in Europe starting back in about February of 2024, and only the factory (or me) can "load" the ability to change it from one mode to the other...