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Reviews For: HF Packer-Amp Homebrew Construction Project

Category: Amplifiers: RF Power - HF & HF+6M

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Review Summary For : HF Packer-Amp Homebrew Construction Project
Reviews: 26MSRP: 124
Description:
Join the HF Packer-Amp Homebrew Construction Project and build a 160-10 Mosfet amplifier, 2.5W in, 35+W out.
Product is in production
More Info: http://www.hfprojects.com/
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00265
KZ3J Rating: 2016-01-28
Fantastic QRP amp! Time Owned: 0 to 3 months.
The HF Packer 35W amp is one of the few linears available if you want to increase your 5W QRP rig's output power. That is, unless you feel like shelling out $700 [ouch!] for an Elecraft 100W linear kit, or you want to buy a cheap Chinese pre-assembled or kit amplifier with little to no output filtering and highly exaggerated output power claims -- not to mention zero customer support and scant, if any, instructions.

The HF Packer amplifier is very high quality (if you do your part), and the customer support is beyond fantastic; Virgil, the owner of HF Projects and the amp's designer, will literally NOT LET YOU FAIL.

You simply can't beat this wonderful little QRP linear!!
WA7NDD Rating: 2015-03-28
Love it! Time Owned: N.A.
Built mine 2 years ago. Use with my FT817. Works every time.
I modified mine before it was the norm to add LED band lights
did it my way before Hf Packer came out with the upgrade. I added 2 fans modifying the fan circuit so that the amp could turn them on at TX, or I could let them run at low speed continually. I do PSK31 with the fans on run Cw and SSB with no problem. I turn the fans off for CW so they don't start with each key contact. easy to build and real value for the money. Mine runs at 35 watts CW and SSB, and turn down the drive on the Siginalink for PSK31 to 20 watts.
ZL2AIM Rating: 2014-10-21
Fun kit to build Time Owned: 0 to 3 months.
I had been thinking of building one of these amps to boost the power of my FT817, IC703 and OHR100A. The latest version is the HF Packer Amp V4 complete with the LED band indicators. This addition of the band indicators convinced me that this was the product to buy.

It took me about 26 hours to build it and another hour to test it and put it in the enclosure. I had one component missing (a pin) and Virgil put one in the post for me straight away. I made one mistake and that was putting the socket for Jumper 2 on the filter board the wrong way around. It was quicker to take the cable pins out of the male socket and put them the other way around rather than trying to unsolder the socket and resolder it the correct way.

It worked first time and gave me the indicated power output as per the specifications. As with any linear amp, you must make sure that you remember to change the band on the amp when you change the band on the rig. Common sense, but easy to make that mistake and blow the mosfets. The mosfets are cheap (less than $2 each.)
I have had cw qso's with ZL's and VK's on both 80m and 40m and had great reports and was told that my signal was clean which is important to me.

For those of you who have a fear of winding toroids it was quite easy but you could always order the kit with prewound toroids for an extra cost.

As all of my HF work is on CW and the fact that I use a memory keyer to do the repetitive calling for me, I was worried that the heatsink might have been overworked. So I mounted a 12 volt fan on some acrylic sheeting with an on/off switch. It keeps the heatsink cool and I only use it occasionally. It might not have been necessary, but I prefer to play safe!

Overall a great kit and of course the added omph of the extra power will help you get those stations that might not hear you with your 5 watts.

Great personal speedy service from Virgil. I highly recommend this kit.
Ian ZL2AIM
AB2EZ Rating: 2014-02-23
A fun project and a great amp Time Owned: N.A.
I just built an HF Packer V4 Rev5 (latest version). It was a fun kit building project, and it works great.

I consider myself to be an experienced kit builder (including kits with small parts on a PC board), and I also understand the theory well enough to cross check against the schematic.

The kit went together smoothly. Total construction time was around 8 hours. I made one mistake (my fault) by inserting a potentiometer into the board backwards. The instructions clearly explained the proper orientation, but I neglected to read that instruction step carefully enough.

To save some work, I ordered the preassembled, low pass filter, toroidal inductor package; and the preassembled cable package.

I would suggest checking the resistance from gate to board ground, on both IRF-510 FETs, before you power the amplifier up for the first time. If I had done that, I would have detected my mistake before destroying one of the FETs with too much gate bias. Fortunately, IRF-510s are very inexpensive, and I had some spares on hand.

I'm having fun with the amplifier in conjunction my FlexRadio Systems SDR 1000 (1W peak power output)... operating in AM mode on 40 meters. The amplifier's gain is around 14dB on 40 meters.

Stu
VE1HAO Rating: 2014-01-12
Virgil goes to extremes to help! Time Owned: more than 12 months.
There is no need to repeat assessments of the quality of the HF Packer Amp. There's a reason it gets all the fives.

But I have to praise Virgil Stamps, K5OOR. He goes to ridiculous extremes to be helpful. I bought an early version of the amp kit, secondhand, about 2003. Finally, almost ten years later, I dug out the box thinking it was finally time to build it, and wrote to Virgil to see if there had been any improvements made or if I should assemble to the original excellent design. I was perfectly prepared to pay for upgrades.

Virgil replied that there had been some changes, and that he would build the latest version. The upshot is that he sent the revised boards and the parts required by the changes FREE!!! Just pay shipping. Absurdly helpful.

Talk about support! I don't imagine that it gets better than this. I think that you can buy anything from HF Projects/K5OOR and be confident that you will get more than you bargained for. Highly recommended.
AE7YD Rating: 2013-12-03
Great Time Owned: more than 12 months.
Radios came and went but my HFPacker is still here.
I now use it with my KX3 with great success even with data mode.
When the conditions are poor the extra punch from this reliable little gem saves the day at nu6i.
NA0L Rating: 2012-10-21
As close to a Heathkit as you're likely to find Time Owned: more than 12 months.
First off, please see the slew of reviews under the QRP Accessories section. The title for this product is not very accurate: this is technically a "group build" project. In effect this product is a kit with all parts supplied, detailed instructions, and excellent, very timely support from Virgil, K5OOR. I built the V3 amp, and have purchased the V4, but have not built it yet. I have also built Virgil's SuperPacker Pro 100W QRP amp, and it's a gem too.

It's difficult to come up with something original to say after reading other reviews, but I wanted to add my comments. Please note the consistent 5/5 ratings! As I put in the header, this is as close to a Heathkit project as you'll find, unless you want to purchase an unbuilt Heathkit on eBay (be sure to have your car title handy).

One item I don't think has been mentioned elsewhere is the amp's internal DC-DC converter. I run QRP while hiking and backpacking and use 11.1 volt LiPoly packs to power everything from the FT-817 on down. When I want to add more power, I carry the lightweight HFPacker amp, which produces full output at down to at least 10 volts.

What else can I say, Virgil's amps are a joy to built and run.

4X1DM Rating: 2012-06-05
highly recommended hf amplifier kit Time Owned: 0 to 3 months.
This review is for the HFPA V4 amplifier. An excellent review of the amplifier was written in e-ham reviews on June 8, 2011 by Glenn DJ0IQ (W9IQ). Unfortunately it appears on this site in the section of QRP ACCESSORIES, when it should really be here. In 2006, I built the older version of the amplifier – the HF Packer Homebrew Construction Project, which I've been using until now (see review I wrote in May, 2006). I just finished building the HFPA v.4 amplifier which is an upgrade of the older one, and which has excellent performance, design and instructions. I don't have much to add to the review mentioned above, but I do want to say what a great help Virgil was to me via email and phone. I did the inventory to see if all the parts were included under poor conditions (on a crowded kitchen table) while visiting my daughter in the U.S., and I thought that two small parts were missing. Virgil shipped them to me immediately, so I could get them while I was still in the U.S., but when I got home to Israel, I discovered that the parts had not been missing after all. All the parts were in the kit, everything was marked clearly and packed neatly, so as to correspond to the order of building. I'm operating QRP CW using the K1 transceiver of Elecraft with an output of 5 watts. When I find the conditions to be poor, I lower the power from the transceiver to 2 watts and use the amplifier to produce 20 watts. I want to thank Virgil for making such a great kit, and for his support while building it. The Yahoo group for this kit is a good place to get help if needed. Just after finishing the kit, while trying to use it, I managed to burn two of the MOSFET transistors by not being careful and not watching the current that flows through the amplifier. Virgil sent me extra MOSFETs with my original order and it wasn't a big problem to replace them. To avoid being in this situation again, I installed a 10 amp fast fuse on the cables supplying the power to the amplifier. I recommend to others to do the same. As explained in the manual, the amplifier has internal protection and the only damage was to the MOSFET transistors.

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Earlier 5-star review posted by 4X1DM on 2006-05-04

Being a radio amateur who likes to use QRP, both CW and PSK 31, I waited a long time for an amplifier like the one designed by Virgil Stamps K5OOR. When conditions change for the worse in the middle of a QSO, this amplifier enables the other station not to lose you. Most QRP kit radios today have excellent receivers, and when conditions get poor, you can still hear the other station, but they lose you. This is the moment when, if you are not “religious” about not increasing power, you wish you could go from 2.5 to 20 watts just to finish the QSO. The HF Packer amplifier gets your power to 35 watts by a flip of the switch (when it is in standby mode). The only requirement is that it be connected to a 10 amp power supply. On most bands, the amplifier puts out 35 watts while draining less than 6 amp. The amplifier’s small enclosure is a marvelous feat of engineering, and the same is true of its operation. Although it is not a simple kit to build, the good instructions available for downloading from Virgil Stamps’ website, together with his help and patience, make it possible for even a less experienced kit-builder to complete the kit. If you, like me, are not good at metal work and/or lack the necessary tools, it is highly recommended to purchase the optional enclosure. Also, to make life even easier one can order all the connecting cables and coaxes already prepared, ensuring that they are well made. The amplifier’s coverage of all the bands from 160 to 10 m caused me to pull out of storage my old HW9 Heathkit QRP radio and hook it to the amplifier (my Elecraft K1 has only 4 bands). One must be careful not to have more than 2.5 watts as input to the amplifier unless the attenuation resistors are changed.
KSAVES2 Rating: 2010-07-27
36V version Time Owned: more than 12 months.
I did the 36V version of the HfPacker and am satisfied. It teaches operating discipline as
it will not tolerate selector mismatch. I get 20 watts out on 10m and 60 watts on 80m with 5 watts in. Keep a supply of IRF510's around which isn't too much trouble as they are $1.50 or less apiece. There are no safety circuits so one needs to keep that in mind but that is to be expected in a package sized so small. Again, in spite of these "quirks" I really like this amp. If I dork it, I, as an electronics moron, can fix it quite easily and be back in business in 30 minutes. The fan only comes on when transmitting and goes off after a bit of a delay.
Pretty easy to build and the extra file has scads of photographs.
HB9LFU Rating: 2010-07-03
Innovative Product Time Owned: 0 to 3 months.
There are some qrp amplifiers and amplifier kits on the market. I have another amp using two IRF510s but even on 80m the output is always well below 30W. None of their designers had the clever idea to double the 12V input voltage and thus get a substantially higher output from the 510s. The circuit boards and parts are of a very good quality and the documentation is excellent. The precut and preprepared connection cables are the icing on the cake. To me this kit even goes beyond elecraft standard.