Date: Thu, 6 May 93 15:05:39 -0500 From: adams@chuck.dallas.sgi.com (Charles Adams) Message-Id: <9305062005.AA10470@chuck.dallas.sgi.com> To: qrp@Think.COM Subject: Oak Hills Research QRP Kits Gang, i have built the following from OHR: (i'm just a crazy kit builder trying to adjust to the lack of a heath supply....) 1. the 20 mtr old qrp kit ($149.95) 2. the OHR 40 mtr Spirit ($198.95) 3. the OHR 30 mtr Sprint ($109.95) 4. the OHR WM-1 wattmeter ($79.95) 5. the OHR Audio Filter ($69.95) not quite sure about this one also a 20 mtr Spirit, but it's not ready yet........ ;-) thought i'd try the visible part of the spectrum above 40 meters...... all the kits are super. the original rig, advertised by Ocean State Electronics and others, is being replaced with a new kit (soon to be announced and sold) called the Explorer. all the kits have double sided, silk screened, green solder masked, plated through holes, etc. circuit boards. good density and compact boards. reminds of the better heath boards. parts are first rate quality. a. the Spirit is my favorite and my full time rig on 40 meters. of course, the antenna is most important here. i use a 80 meter long wire up 10 meters. my hit ratio is over 98%, and this is no exaggaration on my part it has very little to do with my operating skills. i mean, 2 watts is 2 watts is .... if i hear them, and the receiver is HOT, i can work them. i may get beat periodically by someone with more power, but hey, that's what qrp is all about. i don't mind. anyway, i digress again. the qsk solid state switching is just beautiful. [i ran heath hw-16 (a long time ago at 25 watts) for many many years just because it was the first rig to have solid state switching, even though the rest was tubes.] everybody i talk to says the keying is super in the Spirit. talked to a w2 in february. i started the rig cold turkey in a room where ambient temp was 60 degrees. the guy was running a kenwood that had been on for 30 minutes plus. i talked to him for an hour at 40 wpm. neither one of us touched the dial. the temp compensation in all of Dick's, KE8KL, rigs is super. he spends extra time at this. Dick bought OHR from Doug DeMaw some time back. i don't know the dates. anyway, if you can spring the bucks, get this one. 2-5 watts out. i set mine for 2. i thought 2 would be a challenge over 5. ;-) b. the Sprint is a very small version of the W7EL DC rig. output is 1.5 watts. this one is going with me next week to houston for week long business trip. also taking hw-9 to play with. the sprint is on 30 meters and it works rather well. i have some difficulty on my long wire due to rf ground, but i'm working this problem out when i can get some time to play. when at home i'd rather work 40 anyway. the rig is light, sorry i don't have the exact size and weight, but ping me and i'll measure all of the above. no ads on this rig that i've seen. maybe someone from Dayton saw one at the meet. i had Tejas' Backpacker I and never got it to work. the OHR board is the size of one of the three boards in the Tejas. anyone gotten a Tejas rig to work? i talked to a BP II in St. Louis months ago, but the 40 beam the guy had was pointed to the east and stuck there. kinda interesting story. guy was a qrp meeting and he had handed out a copy of a newsletter that i had done to the group that he had gotten from someone i had given it to in San Antonio..... small world. BTW, that doesn't make me famous..... ;-) c. the wattmeter and the audio filter are great. i would not part with the wattmeter for anything other than a brandnew one. in case someone doesn't want to bother with the assembly process. no qrp shack should be without one of these critters. three scales, 10 mW, 1 W, and 10 W full scale readings. 9V powered and i've left the thing on for days at a time and still the battery is going..... the audio filter is the best one around that i've seen. i gave my Autek QF-1A away!! the audio filter is based on the one in a QST article in Oct of 1992. i think that's right.... yeh, that's it. ok, phd dissertation ended. if you want more details, send SASE, 830 Waite Drive, Copper Canyon, TX 75067-8581. i'll try to get ASCII copy to think.com for ftp, but don't hold me to the fire on this one guys. i'm against the wall already on my time line. the explorer is gonna be in the $159-169 dollar class. can't wait to get one. be the first kid on the block to own the whole set. i am just a peachy keen happy customer. i am not paid by OHR or employeed by them in any form or fashion. Oak Hills Research 20879 Madison St Big Rapids, MI 49307 Dick Witzke KE8KL (ex KD7RT) i'd put the phone number here, but then i'd be asking for trouble. ;-) don't want to put him in overload. it's in the mags, except QST. 72 es gl de k5fo, Chuck Adams, K5FO @ 70+ wpm cw adams@sgi.com ====================================================================== Date: Mon, 31 May 1993 09:37:17 -0500 (CDT) From: "Jeff M. Gold" Subject: Oak Hills Spirit Review To: qrp@Think.COM Message-Id: <01GYTJUQ59XEJVFYRS@tntech.edu> X-Vms-To: IN%"qrp@think.com" X-Vms-Cc: JMG Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII Content-Transfer-Encoding: 7BIT Here is my review (totally non-technical) of the Oak Hills Research Spirit: Description: ------------ Single Band kit for 80, 40,30,20,or 15 Curtis Chip keyer (8044ABM) Superhet receiver with diode ring mixer and RF pre-amp 4 pole crystal ladder filter followed by an on board audio filter Switchable HP AGC circuit with manual gain control 2 watts audio output VFO with 8:1 vernier drive Sinewave sidetone oscillator w/frequency and level controls QSK 5 Watts output 12vDC 4"X6 1/4"X6 7/8" weighs 47 oz. 100% complete kit with pre-wound coils, PC boards are quality double-sided and plated through and screened. ==================================================================== OK, that is what it says in the catalogue. I opened the box and checked things out. There is a stack of stapled sheets that are the instructions. There are large part overlays, a chart showing you how to read the resistor codes, a detailed and well thought out parts list. and the schematics. This kit isn't the Heath step by step approach. The first page tells you some general things about assembling the kit and soldering and be careful type comments. The first step is to find all the parts and make sure they have been sent to you. Next you find the Receiver board and then it tells you to put in all the resistors followed by the capacitors. The next steps do go through what you need to do. As the process itself would get more unclear the directions get clearer. After building a number of kits I find I like this approach best. I first check off all the parts and label them on a piece of paper and stick the wires through. This gives me a chance to make sure all the parts have been included, familiarizes me with the parts and gives me a double check about putting the correct parts in the right holes on the board. I check them once while I am going through the parts check off and then again before I place them on the board. I also find that checking off the parts is my least favorite part, and when I do it this way, when I start to build I don't have to go hunting for parts. Since I have started to use this approach, my projects seem to work correctly the first time (except for putting in an audio chip backwards and smoking it.. well no one is perfect and I was able to get a replacement for $2.00 at Radio Shack). I found the way the parts were listed on the instructions made it very easy to identify them and check them off. I found almost all steps in the final construction to be very clear and unambiguous. I do a lot of documentation at my job. I find that most instruction sets have places where the author meant one thing and the words indicate something else. OK, now for the kit. I think there were over 170 resistors in this kit. It took me quite some time and energy to sort out the parts. I found ALL the parts to be of top quality. The enclosure is excellent. I didn't see any hint of cutting corners in any piece that was included with the kit. After building kits from about all kit manufacturers, the quality of the parts in this were the best. I have found that Ramsey uses some quality parts and some real garbage..I think Ramsey's enclosures are real ripoffs. The board was the single item that impressed me the most. Like it says it is high quality plated through. You heat the joint and the board sucks up the solder. The result is that you will be proud to show either side of this board to anyone.. my wife comments on how her needlework is beautiful on the front side, but she won't show the back to anyone, well many of my projects are like that. With this one, I felt like displaying the board in an art show.. what a proud pop I am. The silk screening on the receiver board was ok, but certainly not great.. I found I put one piece in the wrong place because I couldn't read the part #. Well this really isn't a problem, and it was my fault. There is a clear large part overlay that makes it a breeze to build. The receiver board is jam packed with parts.. but the back of the board is layed out so that if you use a fine tipped soldering iron you really shouldn't have any problems with solder bridges. The transmitter board was a lot less dense. The Keyer board isn't plated through and not near in quality to the other 2 boards.. be careful with this one.. I found it not nearly as much fun to solder to as the other boards. Once I got the parts checked off and labeled, I found it very easy to assemble. The first part of the instructions that tell you to put on about 200 parts are a mere 2-3 steps. Then when you put in the rest of the parts the instructions (like assembling the chassis, the final wiring and alignment) are detailed and clear. There are no checks as to whether you have built it right.. like Heath's resistance checks, when you are done, you power up and pray. I was real careful with this kit, but got a little too excited at the final assembly and had put one teeny weeny audio chip in backwards.. boy did I feel dumb.. and when I powered up.. the smoke came out.. it failed the smoke test (or is it it passed the smoke test, but failed to work). It was very easy to spot the mistake, and since the chip was on a socket, it was a breeze to correct. I checked the resistors and other parts that fed it, and no problem at all. The final alignment suggests a frequency counter. I can't ever get the frequency counter in my MFJ antenna analyzer to read such low levels, so I use my 757GX as my alignment tool. You just need to set a coil and a capacitor to set the full 100kc bandwidth for the VFO. I take a piece of copper wire, stick it in the antenna jack of my 757 and hold the loose end over the oscillator circuit. It works just fine. The rest of the alignment had some aspects I have never encountered before. You tune the pitch of your TX out signal and the sidetone pitch (I once again used the 757, put both rigs on dummy load, transmitted and set the Spirit for the same note as the 757. I figured the Yaesu people knew what they were doing and had the proper equipment when they did it). The TX alignment I used my Oak Hills QRP wattmeter and you simply adjust a variable resistor for power level and then 2 coils for maximum output. I spoke with Dick at Oak Hills who suggest you tune it for the full 5 watts out to get the best quality TX signal. Over the weekend I took the case off a few times and tweeked various things. A note about the keyer weighting adjustment. I started at the suggested middle position. The keyer was acting really funky... couldn't really set it right. I turned the weighting adjustment and it is now perfect..one of the better keyers I have used..guess that is why a lot of people use Curtis chips. One of the adjustments that you peak .. be careful that you are on the right sideband.. I didn't have much audio level to my speaker, when I went and re-read the instructions, it had cautioned me about it.. went back and re-adjusted and everything was fine. Ok, now for the real stuff.... how did it work. Well let me tell you that the weekend of the CQ WPX CW contest is quite some time to test out a new QRP rig. The rig puts out a full 5 watts (I turned mine back from a little over 6 watts.. may have to have a friend put the oscilloscope on it to check the signal out). The keyer works real smooth.. full break in.. but has a minor little click in it.. don't think the click is going over the air.. I have listened on another receiver. The receiver at first deceived me and I will need to do some more testing. The bands were really crowded in my QTH. The big guns were using big ammo. The rig doesn't have a narrow and wide CW filter switch. This worried me. During contests it is real nice to have a narrow filter available. I tuned around and noticed that when the receiver got a signal, you really only heard that one signal. At first I thought that this was caused by the receiver being too insensitive. After spending the entire weekend of the contest testing the rig out, I found that if I could hear them on the other rig, I could hear them on the Spirit without other station interference. I am not as of yet a person who possesses enough electronics knowledge to go in and analyze the circuit and do comparisons. I can do extensive "real-life" tests.. which from my experience sometimes had more truth than theory. I worked over 125 stations with my 5 watts and Gap vertical during the contest. I worked to Russian stations, a S50S I think it was, an Italian, a French, Alaska, a bunch of islands, and from the West Coast to the East Coast and some other places in between. After I got the hang of it, I got many returns on my first call.. not bad for 5 watts and a vertical.. used the built in keyer, not my contest keyer and my Bencher paddles. Other impressions: I would have left out the AGC on and off, the RF control and made the keyer an option. I use a straight key most of the time. The rig is BIG and HEAVY. A little smaller than my HW9, but not much smaller. The chassis is solid... lots of metal. I think Oak Hills can keep the best parts of this kit, get rid of the extras, and maybe add a narrow filter and a S meter. I think they are coming out with something like this in the near future. For a station QRP rig, it would be pretty hard to beat this though.. and for portable operation it would also be excellent, a little too big for backpacking. Jeff, AC4HF ====================================================================== Date: Tue, 08 Jun 1993 10:44:31 -0500 (CDT) From: "Jeff M. Gold" Subject: kits To: qrp@Think.COM Message-Id: <01GZ4SETGVJ6K6OU1Y@tntech.edu> X-Vms-To: IN%"qrp@think.com" X-Vms-Cc: JMG Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII Content-Transfer-Encoding: 7BIT Well, I finished my Oak Hills Sprint Friday night and have been testing it out. It was a very quick and easy kit to build. I built in a speaker.. not really worth it.. you need headphones for it (Dick says that is the way it is designed). I tried every power supply I own (very well filtered and regulated) and couldn't use a power supply with it (a problem with Direct Conversion Receivers). I finally gave in and use headphones and a 4AH gell cell. The battery hasn't been charged in some time.. but the little rig doesn't seem to eat much. It took a little getting use to.. my first DC receiver. But I have found that the 1 watt (due to low battery) seems to get out pretty good. If the bands are busy.. forget it... all the information I have read about DC receivers has proven to be correct.. noise and stations are doubled... still have been able to make contacts as long as the band was decent enough.. My Sprint is on 30 meters, and the bands seem to have pretty bad since the weekend. OK.. now for more news: Just got the 624 Kits version of the Gary Breed transceiver that was in the Handbook. It is a parts kit boards. You add your own enclosure and jacks. It sell for $109. Thought it was going to be a bare bones type deal. The circuit board is real good quality and nicely silk screened. The instructions are step by step (good for a beginner), the schematics are computer generated and all pretty and there is a nice parts overlay. Going to build the receiver tonight, I hope. You build then test the receiver before going onto the transmitter. I like this approach. One thing I didn't like about the Spirit was you got all the way to the end, no power off tests, and then you just power it on. 73 Jeff,AC4HF ====================================================================== Date: Thu, 10 Jun 1993 08:26:36 -0500 (CDT) From: "Jeff M. Gold" Subject: Oak HIlls Sprint To: qrp@Think.COM Message-Id: <01GZ7GBJBTT4K6P3DF@tntech.edu> X-Vms-To: IN%"qrp@think.com" X-Vms-Cc: JMG Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII Content-Transfer-Encoding: 7BIT Sorry about the last message.. I am trying a new editor and the key sequence is different. I will give this another try: Oak Hills Sprint: Oak Hills Research 20879 Madison St. Big Rapids, MI 49307 1-800-842-3748 (Orders) Sprint is W7EL Optimized QRP CW Transceiver Single band for 80,40,30 High performance DC receiver Diode ring mixer VFO tuning 8:1 vernier ..covers any 100KHz of band RIT, center dtent Peaked audio filter Sidetone oscillator Smooth QSK 1.5 watts all coils prewound 12vdc 100% complete kit $109.95 ----------------------------- OK, that's what the catalogue says.. I am in no way contected with the company, other then sending them a great deal of my pay check. The boards are plated thru.. the best quality I have soldered.. I am currently building a kit with good boards that aren't plated thru, and boy do I notice the difference. Apply heat and solder and the board sucks up the solder..looks great and makes a real good connection. The directions aren't step by step. More like check the parts off and put them in. The board is silk screened and there is a very nice large parts overlay, so putting the parts in is a breeze. When you have to do more than just put resistors or capacitors in, the directions become more detailed and are very clear. With some help a beginner should be able to do this fairly easily. I like to put the lowest lying parts in first.. not the resistors and then caps as directions suggest.. this way the IC sockets sit flatter to the board. The cabinet is very nice and all plugs and jacks are included. The rig is VERY small. It draws very little current. I have been trying to drain a 12v 4ah gel cell before vacation. I leave the receiver on from when I get home till I go to sleep and have done a lot of operating with it.. the battery didn't have a real good charge to start with.. the rig is still taken a licken and it keeps on tickin. The receiver works nicely. This is my first Direct Conversion Receiver.. quite and experience. I have read all the down sides to them like.. you hear twice as much noise, you must tune to the correct sideband, and it is more likely to get inteference from AM stations.. all this is true. I put the rig on the air last weekend and it took a few minutes to learn how to tune quickly.. the directions clearly tell you the procedure..simply start at the "0" end of the scale and when you get the signal to the "0" side it is the correct side. While tuning around I usually tune past the signal till it is right in the middle of the wave.. the signal disappears.. then make sure by tuning up a little past and then down again to the correct side. It only takes a few seconds and it really seems to be working. I have been getting most people the first shot on about 1 watt. This last week the 30 meter band around here has been real bad. Lots of noise sounding like storms inside the rig. I have still been able to get thru the noise and make contacts. I have had a problem with signals coming over my QSO in the middle so I couldn't hear the other person.. but they could hear me. They were on a superhet.. and only hearing one side of the wave.. I have enjoyed the rig.. it will make a nice backpacking rig.. can use my small gell cell and going to make a new top piece and radials for my portable PVC vertical for the 30 meter band this weekend and take it with me to a conference. I have tested it against a couple of Superhets.. I still like a superhet better.. find them easier to operate and easier to carry on a longer QSO without inteference that really isn't even on your freq. This doesn't mean I don't like the Sprint... I was on it this morning and the bands were behaving a little better and I had a real nice and clear QSO with no problem.. always surprised how well the 1 watt is getting out with the way the 30 meter band has been. 73 Jeff, AC4HF ====================================================================== Date: 07 Sep 93 00:14:29 EDT From: Stan Cooper <71154.331@CompuServe.COM> To: Doug Hendricks Subject: Oak Hills Research QRP 20 Review Message-Id: <930907041429_71154.331_DHQ59-1@CompuServe.COM> Product Review - Oak Hills Research 20 Meter QRP CW Transceiver Kit By Stan Cooper, K4DRD Although I've enjoyed working QRP for the past twenty years using a Ten-Tec Argonaut model 505, there are occasions - vacations and business trips - when I want to take along a small HF rig, but the Argonaut is just too big and takes up too much luggage space. Early last year, with a ten day Hawaiian vacation coming up, a small ad in QST for the Oak Hills Research QRP transceiver caught my eye. The ad offered a 7.5" x 6.25" x 2.5" CW transceiver kit in either 40 Meter or 20 Meter versions for $149.95. Published specifications for the rigs are pretty impressive: SPECIFICATIONS: General: Frequency Range: 14,000 to 14,100 kHz (20 Meter Version) 7,000 to 7,100 kHz (40 Meter Version) Transmit Offset: 700 Hz Mode: CW Power Requirement: 13.6 VDC (Negative Ground) Power Consumption: 700 ma at 2.5 Watts Transmit 60 ma Receive (no signal) Antenna Impedance: 50 ohms T/R Switching: Semi-Break in Sidetone Frequency: 700 Hz Active Components: 7 ICs, 14 Transistors, 13 Diodes Transmitter: Final Power Output: 2 - 3 Watts Final Output Stage: 2SC1909 or 2SC2092 Receiver: Circuitry: Single Conversion Superheterodyne, IF: 9 MHz Sensitivity: .25 V Selectivity: + 1 kHz @ (-6 dB) 4 Pole Crystal Ladder IF Filter Integral, Switchable Active Audio Filter: 1 kHz With 700 Hz Center Frequency RIT: + 1.5 kHz Audio Output: 500 Mw I chose to order the twenty meter version, partly because of the DX potential on twenty and partly because of antenna restrictions. Also, my recollection of QRM from high powered broadcast transmitters on forty meters when I was a novice is still vivid in my memory. Assembly - The kit arrived several days after I'd placed my order. After inventorying all of the parts, I began assembly. The kit is built around a single printed circuit board, and all coils are prewound. Although the instructions are not detailed "step-by-step" procedures with profuse illustrations like the old Heathkit manuals, they are adequate, and I managed to get all of the parts properly mounted and soldered to the PC board. One complaint I have is the number of jumpers on the PC board. There are twenty six jumpers, and they are not clearly shown on the parts overlay illustration; the two ends of each jumper are labeled, but one must locate the label for one end, then look at a very "busy" drawing for the label identifying the other end. Finding the locations of each of the jumpers was very time consuming, and this task could have been made much easier had the jumpers themselves been drawn on the parts overlay illustration. By contrast, the NorCal 40 QRP transceiver has only four or five jumpers - a sure sign that Wayne Burdick, N6KR, put a lot of thought into the board layout. Assembly took place non-stop over a Saturday afternoon and evening, and I decided to wait until Sunday morning to apply power. The checkout and alignment instructions call for the use of a voltmeter, frequency counter and an oscilloscope, so if these aren't part of your tool box, you should probably arrange to borrow them from a neighbor before attempting alignment. The VFO coil, L1, is the only coil not "doped" from the factory, and the reason for this is that the winding of L1 is compressed or expanded on the toroid core to obtain the proper VFO frequency before doping by the builder. I spent about an hour tweaking the L1 winding trying to "bring in" the VFO frequency to the required 5 MHz with the tuning capacitor plates fully meshed. I finally gave up, wrote a brief note to the folks at Oak Hills Research explaining my predicament, and shipped the unit back to the factory for check out and alignment. The OHR people called me to let me know that after they had adjusted L1 (admittedly a tricky procedure), the rest of the alignment was uneventful. They even complimented me on my work (nice soldering, no wiring errors, etc.). The cost for their efforts was a very reasonable $28.00, including return shipping charges. Operating - The rig arrived by UPS several days later, and I fired it up minutes after opening the box. I live in a twentieth story apartment, so my antenna options are pretty limited. I'm currently using a pair of "Hustler" mobile whips with 20 meter resonators, configured as a dipole. Using this antenna, I worked several states in the first few hours on the air with the OHR rig. It was (and still is) a real thrill to use this tiny rig, powered by a twelve volt gell cell, to work DX as far away as Latvia. I've found the rig very easy to use, and on-the-air reports of the signal quality have been gratifying. I'm consistently told that the signal is steady as a rock, without any sign of chirp, and - when powered with an AC supply - hum free. QSK characteristics are excellent. Receiver audio is adequate when used with a quality eight ohm impedance headset, but I bought a Radio Shack eight ohm speaker with a 12 VDC powered eight watt internal amplifier (part number 21-541) for use with the rig, and have come to prefer the speaker. Oak Hills Research also offers a keyer kit which may be built into the transceiver. I opted to build the keyer into a separate minibox since I wanted to use it with the Argonaut as well as the OHR rig. The keyer is built around the Curtis 8044ABM keyer chip and costs $29.95. Control Layout- The OHR QRP rig controls are nicely laid out, with the vernier VFO frequency dial located in the center of the front panel. The audio volume control with On/Off switch is in the lower left corner of the front panel, and the headphone jack is mounted directly above it in the upper left corner. The receiver incremental tuning (RIT) knob is in the lower right corner, and the audio filter "narrow/wide" switch is located in the upper right corner. The antenna connector, an SO-239 type, is located on the rear apron along with the key jack and 12 VDC power jack. Summary- The OHR QRP rig is well designed and a real ball to operate! In spite of my complaints, I believe anyone could assemble the kit and get it on the air. Although I haven't tested the unit's specifications, I have no reason to believe the manufacturer's published specifications aren't accurate. The receiver is hotter than a pistol, and the transmitted signal gets glowing reports. Manufacturer- Oak Hills Research Phone: (616) 796-0920 20879 Madison Street Big Rapids, MI 49307 ====================================================================== PRODUCT REVIEW -- OAK HILLS RESEARCH "QRP SPRINT" by KR8L, MI QRP #M-98, NW QRP #127 The Oak Hills Research (OHR) "QRP Sprint" is a single band CW transceiver kit based on the W7EL Optimized QRP Transceiver. The W7EL design, which features 1.5 watt output, full break-in, sidetone, RIT, and a direct conversion receiver, was first presented in the August 1980 issue of QST. The design has been updated since that time and was republished by the ARRL in QRP Classics (1990) and the ARRL Handbook (1993). The kit is available from OHR in 80, 40 and 30 meter versions at a cost of about $110.00, plus shipping. I recently purchased and constructed the 30 meter version of the QRP Sprint. First Impressions I was very pleased with the kit from the moment I opened the box. The cabinet is a rugged affair made from heavy gauge aluminum and finished with an attractive, durable paint job. The circuit board shows similar quality with a silk-screened component side and plated-through holes. The parts layout is well thought out, and no wire jumpers are required on the board. Individual components are well marked with small parts packaged in plastic bags or on tape strips. Despite the small size of the cabinet (5x5x2+ inches), OHR has chosen to use an SO-239 for the antenna connection and one-quarter inch jacks for the headphones and key, rather than the smaller, less robust RCA and one-eighth inch jacks. A full parts inventory and parts layout diagram are included along with the assembly instructions. Construction The QRP Sprint is a relatively easy kit to construct, although I might hesitate to recommend it to someone with no electronics building experience at all, primarily because of the compactness and close component spacing. Installation of resistors and capacitors is accomplished in whatever sequence the builder chooses using the parts list, schematic, and parts layout as guides. Installation of inductors, semiconductors, cabinet mounted components, and interconnecting wires is directed in a step-by-step fashion. All toroids are prewound. Most builders will find a magnifying glass helpful to read component values (particularly on the monolithic capacitors) and to make inspections for poor solder joints and solder bridges. Alignment is simple and straightforward, requiring only a frequency counter, wattmeter, and the appropriate non-metallic tools for adjusting slugs in the tuned transformers. Operation My QRP Sprint worked just fine the first time I turned it on, and I managed to make a contact with my first call. I attribute this at least in part to my practice of making frequent checks, double checks, and triple checks as components are installed on the board and both before and after soldering them in place. I have made solid contacts all over the country and as far away as eastern Europe using nothing more than a six-band vertical. The small size, light weight (18 ounces), and low current requirements (40 milliamps on receive and 240 milliamps on transmit) make this an ideal camping or backpacking rig. A pair of 6 volt lantern batteries will provide for many hours of portable operation. The main tuning control is smooth and linear, and the CW beat note is a pleasure to listen to. Selectivity is limited and, of course, the direct conversion receiver provides an audio image, but the quality of the CW note, combined with proper use of the RIT, make it possible to copy under even relatively crowded band conditions. The solid state QSK circuit has to be heard to be believed. OHR describes it as "silky smooth" and this is no exaggeration. The rig is very stable mechanically, with no hint of microphonics or hum. My only complaint has been a relatively large amount of thermal drift in the VFO (about 700 Hz in the first 20 minutes), but the rig settles down pretty well after it warms up. I think that a certain amount of thermal drift is probably unavoidable in a VFO running at 10 MHz, and I would not be surprised to find that the 80 and 40 meter versions are much more stable. During on the air use I have not found the drift to be a problem. Product Support The QRP Sprint replaced another W7EL-based rig in the OHR product line, and my kit was one of the first ones shipped. During the initial alignment I was only able to achieve a tuning range of about 10.050 to 10.150 MHz, rather than the specified range of 10.100 to 10.200 MHz. I called Dick at OHR and he agreed to review the problem. The next day he faxed me the results of his analysis, and indicated that he was sending me a replacement for one of the fixed capacitors in the VFO. Within a few days I had the new part installed, the alignment was completed successfully, and I was back on the air. Oak Hills Research sells a number of QRP kits and stocks a variety of components for the QRP homebrew enthusiast. A catalog may be obtained by writing to them at 20879 Madison Street, Big Rapids, MI 49307, or by calling (800) 842-3748. ====================================================================== Date: Mon, 16 May 1994 13:07:26 -0500 (CDT) From: "JEFF M. GOLD" Subject: Oak Hills Classic To: qrp@Think.COM Well Sunday I got my Oak Hills Dual bander going. The directions and actual building were a really relaxing and enjoyable experience. There were NO ambigous directions including the alignement. The alignment was a little tricky and I may have one or two very minor readjusts to do. I found only one minor error in a diagram (but text directions were completely correct) and Dick is going to change that. The whole kit was top grade. Needed to be built slowly.. not too much fun to debug once you are done with the plated thru boards. The bands were in bad shape yesterday, but had no problem on either 20-40. Had a nice 40+ minute chat on each band, worked some contests (not sure which ones, but they seemed content with 599 and a serial number). Worked Netherlands. The receiver seems to work extremely well. The QSK is GREAT, the Curtis keyer works .. well like a Curtis Keyer (no complaints). The power is adjustable from the rear down to about nothing. Mine putting out a nice clean 5+ on 40 and little under 5 (but right about at it) on 20 meters. The rig has a very nice sidetone that is adjustable (I like a very low sidetone level when I operate for long periods of time). The rig has seperate jacks for straight key and paddles (if you have keyer option). The rig doesn't have a built in speaker.. after a long period with the headphones (I am not a headphone person) I simple plugged my amplified speakers into the headphone jack and it worked great). The audio seems to be enough to drive a speaker (i wired one or two into the jack and seemed ok). Got very good reports on my signal and it sounded great listening to it on my kenwood 850. If you have built before .. this is one of the best/most fun kits I have ever done. The only minor downside is that although the directions were extremely clear, there is no circuit descriptions...I am not a whiz with schematics.. when trying to figure out what I was really doing in the alignment and how the rig worked it took me a while.. but other may just be able to look at the schematic. I talked to Dick at Oak Hills and told him to think about including circuit descriptions. 73 Jeff, AC4HF