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Hello all!
QRZ, is the frequency in use? Last night, on a whim, I ordered a uBITX v6 from India. Anybody know how fast they ship? Kicking myself this morning because it's also carried by gigaparts, which would surely get it to me faster :). My name is Jerry, callsign KF6VB. I've been a ham since 1970 or so. Never been much good at CW, but I did earn the extra with code in the mid-80's. My interests are homebrewing and ragchewing. Not much for contesting - which seems to leave me out of most ham activity these days. I have a solid technician-level background in electronics and a 20 year career in embedded software engineering. At this time, I have a 6BTV vertical up the hill behind my house. It is grounded with an "Ufer ground", which is about 80 feet of 6-gauge copper wire embedded in the concrete pad. The pad is ten feet wide by 70 feet long. The vertical is fed by an automated MFJ998RT remote autotuner. The tuner was needed because the coax down to the house is 300 feet! The Ufer ground is extremely effective - so much so that the tuning on 80M was too low, and I had to chop about a foot off the top whip - directly contravening the dictates of the manual. I am already thinking about upping the power. QRP is fun in principle, but I've found it quickly becomes frustrating ( and not conducive to ragchewing ) when people don't hear me. Ebay is crawling with cheap linear amplifier cards and kits. I see one vendor who has a three-board kit including the per-band low pass filters and Tx/Rx switching. The one I'm looking at is 600W. That's a good power level IMHO - only a few dB below legal limit, and easily drivable from a standard 125VAC outlet. - Jerry KF6VB |
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Jerry,
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Name here is Jerry, KE7ER. A ham since the early 1970's. Mostly interested in the technical puzzles, typical SSB contacts are not very motivating for me. Not sure what current shipping times are. Mumbai is in the thick of a Covid19 outbreak, that may or may not have significant impact. In the past, many have reported receiving via DHL in around a week. The uBitx is a hackers delight, a brief look at this forum will tell you that. It is primarily an SSB rig, CW is an afterthought.? (Consider the QCX if you want a good cheap CW rig.) There is no QSK for CW, and the first dit of each transmission might get clipped off depending on the firmware used. The CW keying envelope on the stock rig is rectangular, there will be key clicks which would be problematic when driving a 600W linear. In SSB mode, IMD and various spurs can pop up if you give it too much mike gain, I'd want tools to monitor signal quality if boosting to 600 Watts. Where the uBitx shines is as a learning tool.? Many in the forum have modded it, broke it, and then fixed it. And came out the other side quite a bit smarter. I'd be afraid to take the covers off a $1k+ HF transceiver, on the uBitx they come already off. The Ebay linear amps are often, well, ebayish.? Buyer beware. Often come with no instructions, and often must be modified extensively to work at all. Power out may be a fraction of what is claimed. A high power linear will likely require more power going in than the uBitx has to offer. Some in the forum have succeeded with ebay amps, you might ask here for advice. Some have not. I'd recommend playing with the uBitx barefoot first. Sounds like you have a great antenna, should make plenty of contacts. Jerry, KE7ER On Fri, Apr 9, 2021 at 11:24 AM, jerry@... wrote:
Hello all! |
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On 2021-04-09 11:59, John Cunliffe W7ZQ wrote:
If you had ordered from Giga Parts in the US for the same price you*** Yeah, rub it in :). - KF6VB John |
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Jerry
Hang in there, and perhaps this way more of it goes to hard working people who kit these. It is quite an interesting rig, but not one I would necessarily recommend for 600 watt operation. Most 600 watt amps need more than 10 watts input, but its possible. Ubitx sometimes have higher spurs than other rigs. Most of us have one for fun.? Lots of digital modes now. Lots of activity. If you can land a 100 watt rig its a great start.? Don't give up on cw. We have a blast in soccer. Curt wb8yyy |
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On 2021-04-09 14:14, Curt via groups.io wrote:
Jerry*** It's not about needing a rig. It's about having fun. Stuck at home, bored because of COVID. I have a TS590. And an Icom IC706MKII. And a collection of SBE 34 transceivers - some working, some less so. And some ARC-5's in storage. I did order the linear kit. It takes 10W drive for 600 out. Might regret that. Somebody built a new house about 70 feet away from my antenna. Big house, with every gadget known to man. In the mean time, I think it would be really nice to have a little amp that just sits in the corner and quietly - no fuss no muss - makes 600W. I do have a couple of big tube amps - a 30L1 and an Alpha 78 - but they're just too big and noisy to use in the bedroom. They're more like "garage" equipment. Don't give up on cw. We have a blast in soccer.*** I do like CW. Just not that good at it :). Back in the 80's I used a CW training program on my TRS-80, and got up to 22WPM with code groups. The Extra test was just 20WPM, and plain text. - Jerry |
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Name here is Jerry, KE7ER.
A ham since the early 1970's. A pleasure, Jerry! The uBitx is a hackers delight, a brief look at this forum will tell*** Yes, that was the primary driver. I *love* open source software and hardware. It is primarily an SSB rig, CW is an afterthought.*** I wonder if the old "audio oscillator CW" trick would work? if you want a good cheap CW rig.)*** My TS-590 works OK for that :). There is no QSK for CW,*** I'm honestly not that fond of QSK. Semi-break is fine for me. The CW keying envelope on the stock rig is rectangular,*** Yeah, that's bad. there will be key clicks which would be problematic when The Ebay linear amps are often, well, ebayish.*** I ordered the amp. It uses a pair of MRF300's for 600W out. The seller ( dxworld.e ) has a Youtube video showing it being tested, with 600W out. Drive was 10W. It comes with a bank of switchable low pass filters. This seems to be a serious vendor. I also ordered a 50V 20A power supply. So I need to dream up a case and a heatsink. Seller claims 80% efficiency. On the back of the envelope that works out to 750W input, 600W out, 150W dissipated as heat. Maybe a copper spreader coupled to a big CPU cooler? The linear comes without the power transistors. That's OK, I can source them from Mouser etc, and they're AMAZINGLY cheap. I have a case from a Heathkit "Single bander" SSB transceiver, that should be just right. If the uBITX is too dirty, I can stil use the linear with my other rigs. The TS590 has a"power" control, and can be turned down to 5 watts. I recently got a little tiny spectrum analyzer - it should work fine for checking for spurious. - Jerry KF6VB |
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Jerry, KF6VB
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> *** I wonder if the old "audio oscillator CW" trick would work? It was used for years on the *Bitx* transceivers, but adds opportunities for distortion, a not quite suppressed carrier, opposite sideband leakage, spurs due to mixer products. In short, all the various troubles one might have with SSB. Generating the CW signal at the operating frequency avoids all of this. It would be relatively easy to add CW envelope shaping, but nobody has yet bothered since it isn't much of an issue at QRP levels. (You would also need envelope shaping on your audio oscillator.) ... And CW is an afterthought for the uBitx. > *** I ordered the amp. It uses a pair of MRF300's for 600W out. That sounds like a fun and challenging project. Let us know how it goes, I'll be very curious. > I recently got a little tiny spectrum analyzer The tinySA is a very useful tool. However, not quite enough resolution to check for IMD. Best Regards, Jerry, KE7ER On Fri, Apr 9, 2021 at 03:23 PM, jerry@... wrote: Name here is Jerry, KE7ER. |
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Dave.Pro2nd
Sent from ProtonMail mobile -------- Original Message -------- On Apr 9, 2021, 8:00 PM, Skip Davis via groups.io < skipnc9o@...> wrote:
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Skip Davis
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