|Just an addiion to my previous review in that|
you can make make a TERRIFC improvement to the
tuning scheme by subtituting a Varicap and a Ten Turn Pot for the polyvaricon tuning scheme
It is a simple, NO BRAINER MOD that *anyone* can do, takes 5-10 minutes, makes tuning smoother and easier, and even extends the bad coverage of the rig. Just Google "MKARS80 Varicap Tuning Mod". There are other mods out there too tht I am going to try: A simple audio AGC mod.
AND, Radio-Kits-UK offers a kit to allow you to use the MKARS80 on BOTH SSB *AND* CW.
Way to go Steve!\73, Ken AD6KA
Earlier 5-star review posted by AD6KA on 2010-07-10
This rig is one of the best kept secrets in the QRP community. It's a really classy, inexpensive, high quality FUN BUILD with great performance. And there is a CW Adapter for it on the way!
The MKARS80 is by far the best QRP kit to come out of the UK. Despite the low price (55 GBP approx USD $85) the plated through, well silk screened PC board and all parts are first rate. Elecraft or Hendricks class. The instructions (downloadable from site) are very thorough and in the same class, with many illustrations. All that is needed for alignment is a DMM, Big Rig (and a QRP power meter is helpful). Tuning is by one-turn polyvaricon, and there is a fine tuning and RF gain controls. So a vernier dial or reduction drive is a good idea, though not critical. Power output is easily 5+ watts on peaks from the IRF510 MOSFET final. Though the specs say it covers the UK 80m Phone Band 3.8-4.0 MHz, I had NO TROUBLE adjusting the polyvaricon and C83 to cover 4.0 down to almost 3.6 Mhz. Utilizes a user supplied inexpensive (electret) computer mic. I rolled my own with an electret element, momentary push to close button switch, and a pill bottle. Suit yourself, I used the junk drawer! BEST OF ALL basic price includes a 2 line Digital Frequency Display that also reads battery voltage!! And the undrilled enclosure is only a $7 option. Unheard features, performance and value at this price range. Performance is very good.
Of course 80m QRP SSB is not a cake walk, but I have made a lot of nice QSO's, both during contests answering CQ's and even sending out a few CQ's of my own on non-contest weekends.
Rig went together smoothly. There are quite a few parts, even though it calls itself a "simple" rig. There are some very small toroids & transformers to wind using #38 enameled wire. Sounds trickier than it is, just go slow and steady. Steve, G6ALU is ready with a quick email to answer questions and there is also a Yahoo Users Group. What else could you ask for? If you are into SSB QRP, this is a nice rig to have with the conditions on the higher bands being what they are at this time.
Only had one problem, was a small one with alignment. Sent Steve an email, he shot back to check one of the transformers, and sure enough, there was a cold solder joint on that exact part he told me to check. Bingo!
These days when a lot of QRP manufacturers are forcing you to buy overpriced enclosures and things you don't want or need, it's great to have someone offer a reasonabl, priced high quality kit rig with the "Board and Parts Only" version. SWL is about the only one left who does this. $30-$50 for an enclosure is insane! $7 is not.
Can't say enough good things about this rig.
You'll just have to try it for yourself!