45W HF Power Amplifier For YASEU FT-817 ICOM IC-703 IC-705 Elecraft KX3 QRP Ham

The amp was the only one offered by Amazon so we had little choice of one to buy for my new IC705 qrp radio. I thought the price was high at $270 as the per watt versus $ is quite high. If the RM Itally ones were on Amazon I'd a bought that one from RM Itally. But I ended up with this one. The power cord does not disconnect. It just hangs out a grommet along with the tx relay wires. The TX or ptt wires have no connectors on them. An RCA connector, Yaesu ptt connector and a 1/8" head phone plug comes with it to be put on the ptt wires. I wired the ptt hot to the tip and then the ground connections to the shield of the supplied 1/8" stereo plug. No connection to the ring contact as that is ALC from the IC705 and not avalible on this amplifier. But this ptt from the IC 705 runs this amplifier ptt input easily. It takes about 15 to 20 milli Amps on the key line. And I was quite happy with that. I ran my drive power to the amplifier up till the dc amps on the 12v powerline of the amplifier did start to plateau. That does happen about 6 Amps dc with about 3 to 4 watts of drive from my ic705. Using BTW the rear mounted battery of the IC705 radio.This typically gives me a 57 contact with the amplifier at 35 watts output. Without the amplifier many stations with 5 watts ssb the other station needs to be something like a S10 on the meter before we will have a good contact at 5 watts out on my end. This 35 watt amplifier changes that. I've had noisy stations hear me well and I could hardly copy them.It's a tough little box and I figure you'll like it. Jimmy,wx9dx

Very satisfied with this unit. Have bought 3 from different vendors and no difference noted. Buy it cheap and enjoy.

This amplifier is just fine to own and use for the intended purpose (ham radio). It is completely legal and perfectly acceptable to use this amplifier for ham radios. Those who are writing comments to blast it as 'illegal' have no idea what they are talking about.First of all, this amplifier does not use RF sense for TX signal. It requires an accessory signal from the radio. Though this is not difficult to achieve with a little ingenuity, it meets the requirements of an HF amplifier that is sold in the U.S. FOR HAM RADIO USE.Secondly, nobody is buying this amplifier for illegal use on CB frequencies. At 45 watts CW/SSB, your output power on AM would be just a couple watts more than a stock CB is capable of. Absolutely not worth the price tag to gain a fraction of a dB. If CB'ers ARE purchasing this amplifier for use, it probably puts out a cleaner signal than the trash mass produced CB itself. I don't condone this use, as it is illegal (and a waste of money).This amplifier works great for hams who want to boost their QRP rig output for rough band conditions. It interfaces easily to almost every rig I can get my hands on. And it does it for a decent price when considering that you are getting a multi-band linear amplifier (capable of SSB).

I bought this to get a few more watts using the Icom IC-705. QTH is KH6 so a little more RF helps sometimes. With 5 watts in I get about 40 to 45W out depending on the band in use. Comparing other small amp on the market, I think this is a pretty good value.I had no trouble getting the relay cable wired and so far (3weeks of operation) it’s performed perfectly.

these are excellent little amps for QRP rigs... most come with an 817 keying cable, but you can easily make up a cable for your rig - with the exception of the 703, which requires transistor circuitry to protect the rig's relay (w2eny sells the cable)i made up cables and can use this amp with my Xiegu G90, X5105 (use the ptt con on the ce-19), Elad FDM Duo, Commradio CTX-10, 818, Elecraft KX2, and Ten Tec Argonaut VI.. i also recently acquired a 705, and set up an RBI-1 buffer... but a simple stereo cable to amp for keying also works!

Will not work with ic705! Requires a home brew current amplifier to switch it to transmit.

Contrary to the description, it will be a problem using it with an IC-705 due to the keying lead current without some kind of buffer. Works ok with FT-817 but output protection is somewhat fragile. Be very cautious of the VSWR of your antenna system. As far as the legality of the amplifier, reference 97.315 and 97.317 of the FCC Rules. Basically, it is legal for amateur radio operators of the proper class for HF bands but is illegal for other uses like CB radio. Be careful of the spectral purity of the input as if the input is dirty, it can cause "spurious emissions" in excess of fcc regulations.§ 97.315 Certification of external RF power amplifiers.(a) Any external RF power amplifier (see § 2.815 of the FCC Rules) manufactured or imported for use at an amateur radio station must be certificated for use in the amateur service in accordance with subpart J of part 2 of the FCC Rules. No amplifier capable of operation below 144 MHz may be constructed or modified by a non-amateur service licensee without a grant of certification from the FCC.(b) The requirement of paragraph (a) does not apply if one or more of the following conditions are met:(1) The amplifier is constructed or modified by an amateur radio operator for use at an amateur station.(2) The amplifier was manufactured before April 28, 1978, and has been issued a marketing waiver by the FCC, or the amplifier was purchased before April 28, 1978, by an amateur radio operator for use at that operator's station.(3) The amplifier is sold to an amateur radio operator or to a dealer, the amplifier is purchased in used condition by a dealer, or the amplifier is sold to an amateur radio operator for use at that operator's station.§ 97.317 Standards for certification of external RF power amplifiers.(a) To receive a grant of certification, the amplifier must:(1) Satisfy the spurious emission standards of § 97.307 (d) or (e) of this part, as applicable, when the amplifier is operated at the lesser of 1.5 kW PEP or its full output power and when the amplifier is placed in the “standby” or “off” positions while connected to the transmitter.(2) Not be capable of amplifying the input RF power (driving signal) by more than 15 dB gain. Gain is defined as the ratio of the input RF power to the output RF power of the amplifier where both power measurements are expressed in peak envelope power or mean power.(3) Exhibit no amplification (0 dB gain) between 26 MHz and 28 MHz.(b) Certification shall be denied when:(1) The Commission determines the amplifier can be used in services other than the Amateur Radio Service, or(2) The amplifier can be easily modified to operate on frequencies between 26 MHz and 28 MHz.[71 FR 66465, Nov. 15, 2006]