On Tue, Aug 13, 2024 at 08:06 AM, Mikek wrote:

Also the adjustment will be less touchy, easier to set.

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Looks like you were promoted to "Owner" in more than one of Steve's groups.

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Andy

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On Tue, Aug 13, 2024 at 09:49 AM, wn4isx wrote:

I logged into Groups IO like normal and there is a blue box with owner inside.

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Does this mean I've been elevated to group owner by mistake?

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Yes, that does mean the group's original Owner (Steve Greenfield) has selected you as one of the group's Owners.? An Owner is like a super-Moderator.? You have the power to create and destroy.

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You might recall Steve wrote that he had a recent stroke.? I think he wants to make sure at least a few active group members are able to carry-on in case he can't for some reason.? I think he did not do it "by mistake", but I am not him.

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As one of the Owners, you don't need to do anything.? Just don't screw it up by deleting things that should not be deleted.? And hopefully you will be with the group for a while so that you could - if needed - step in if Steve can't.? The problem with some groups is that they have only one Owner, and if that Owner goes missing for any reason, the group dies and can't continue like it used to.

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You will probably start to receive auto-generated messages whenever anyone joins or leaves the group, and several other status messages.? You can ignore them.? You can even disable those messages, and act as if you are a normal member.? Heck, I think you can even edit your own membership status so that you go back to being a regular member again and not an Owner, if that is what you want.

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If you want help knowing what you can do, I may be able to help a little with that.

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Andy

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I hope I'm not puttng my foot in my mouth but I didn't realize Andy had passed away...I thought he simply retired.

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Jay

On Tue, Aug 13, 2024 at 04:49 AM, chris.sentance wrote:

4. A number of designs include two 51ohm resistors across the output of T1 running to ground in parallel with a 100ohm trimpot but I don’t understand? why both??

It may be as simple as a 100Ω pot was more available than a 50Ω pot.

Also the adjustment will be less touchy, easier to set.

???????????????????????????????????????????????????? Mikek

On Tue, Aug 13, 2024 at 04:49 AM, chris.sentance wrote:

In some designs there are 2 series (parallel) diodes between the diodes connecting the loop connection to ground and some just have a pair of parallel 1N4148’s. I presume the latter is correct.

If you want to protect the loop against static atmospheric voltages to earth, you need to connect the diodes to ground. Ground means real ground/earth, not GND/minus of the amplifier.

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regards

Fred

Hi everyone

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As the owner of an ageing ALA1530LN since Wellbrook ceased trading I have been trying to find a replacement amp unit before mine finally succumbs to the wet & windy English weather.? With the sad death of Andy Ikin we know there will be no possibility of the design being sold and marketed and I have seen with interest a number of variants ranging from the Chinese clone Wellgood ALA1530LN to a number of recent schematics on this board yet all seem to vary slightly making it difficult for a novice such as myself to try to construct a new head amp.

My ultimate aim is to produce a new head amp for personal use only that will fit into a 65mm round conduit box that should retro-fit direct into my existing loop, and so as a first step I have produced a schematic drawing upon a number of the existing circuits to produce a compromise design for an ALA1530LN clone and I have uploaded it to the files section here:

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/g/loopantennas/files/ALA1530%20combined%20schematic.pdf

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As this is still a work in progress I haven’t indicated transformer phasing dots yet.

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There were, however, some design questions that I hope other members might be able to clarify:

1. Ferrite beads – there seems to be a variation in the value of ferrite beads used and I wondered how critical their value was?

2. In some designs there are 2 series (parallel) diodes between the diodes connecting the loop connection to ground and some just have a pair of parallel 1N4148’s. I presume the latter is correct.

3. Some circuits show a single 82pF across the loop in connection whereas most show each loop connection having an 82pF connection to ground.? Again I assume the latter to be correct.

4. A number of designs include two 51ohm resistors across the output of T1 running to ground in parallel with a 100ohm trimpot but I don’t understand why both?? If the source voltages on Q1-Q8 need to be equal then surely just the trimpot will suffice and if the exact voltage id not absolutely critical then I would think the trimpot could be omitted.

5. Some designs have a 10pF capacitor across the output of T2 but most do not, presumably this serves little purpose?

Sorry for all of the questions and I hope members might be able to help with my lack of knowledge.

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Thanks in advance

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Chris Sentance

Doesn't using ExpressPCB lock you into using their manufacturing service, at least for the first order?

Thanks,

Craig

Ill bore you with the physical exam yesterday. The physical therapist met us at the orthopedist's office with the surgeon and 2 x-ray techs. I thought I knew what torture was, I've now had a post doctorate class. The surgeon had the PT maniac positioned my left leg/knee in positions neither nature or God intended to "Get good X-rays."

The surgeon want to insure he has the best fitting "joint." Normally they use "full step sizes" but you can special order 1/8 step sizes.

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Given I had my right knee repaired on June 4 and that leg is now almost a full inch taller when standing because my left leg is bowed like I rode a horse from birth, the surgeon is concerned the extreme difference will cause excess wear on my hips. So I now have this really odd spacer I have to attach to my left shoe to sort of equalize things.?

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My wife made video of me walking without the spacer and it looks like some sort of comedy routine from the Ed Suliven show from the late 1950s. The spacer helps in many ways but throws my center of gravity off even more.

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When I was a child the medical community was honest and didn't care about hurting feelings and called it "clumsy child syndrome" today they've gone all sensitive and it is dispraxia.

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I'm certain if you look in an old medical book you'll find my photo as Exemplar Type 1, Male by the clumsy child entry. I'm probably the only person you've ever heard of who broke his arm tripping on a shadow in the ER. Greenstick fractured my left arm as we were leaving after they removed the cast from my right arm.

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My wife once asked me to dance with her and started giggling so hard I thought she'd pass out,?
when she recovered enough to speak, "Honey the Funky Chicken was written about you." [She was way too kind. Although I can waltz.]

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As we left the practice I swear I heard the orthopedist mumble about ordering 30 yards of bubble wrap.....

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Just think I've made it 72 years, 32 come August 31, rode a motorcycle for 30ish years, had one accident, truck pulled in front of me and I can't walk across a floor with a pattern on it.

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Our cat just shakes her head as I stumble by.

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In a way it's funny, my right knee hurts if I move it certain ways, so I don't do that, but my left knee now feels like I have demons with tiny nail guns. It gets worse at night when I lay down.?

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Getting old ain't for sissies.

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In PE I drove the coach to tears. I could sink a basketball from anyone onside of the center line, but I couldn't dribble to save my life. And I've taken mountain climbing lessons at Grandfather's Mountain in NC, and I'm terrified more then 3 feet off the ground, which given my total lack of coordination is a survival instinct. My then girlfriend, now wife, insisted it'd be fun. It was, sort of, everyone should free repel 200 feet, once.

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And just think I'll two matching scars down the center of my knee, ~3" above to ~3" below. There goes my career as a knee model...unless of course they are hiring for Frankenstein's Monster. The scar freaks people out. I'm having to wear support hose on my right leg to help the swelling, about 1 in a gazillion people have edema for unknown reasons. I had a young girl at the library ask me "Are you a pirate?"

?I had midlength shorts, and I did sort of look like a man from ~1800 with one legging. I smiled, "No dear, just a booboo."

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I thought the mother wanted to find a hole to dive in.

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I used to walk sort of like a drunken sailor, swaying side to side, now I only sway to the left....and I'm conservative!

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If you can't laugh at yourself you won't survive. I ought to make it to 200.

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Serious note on knee replacement, it isn't for all orthopedic conditions, but, if? you need it, get it!

My right knee is pain free 99% of the time, on June 3 I could not stand for more then a minute or so, my right knee would "give way", I might have been able to walk 300 feet. Today I can stand on the right leg...one legged and Friday morning I walked one full loop, ~900 feet, on the walking loop at the pool. With zero pain in my right knee!

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We won't mention my left knee.

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Hi everyone

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I just wanted to thank members for their schematic/PCB design suggestions, I am getting reasonably good results using ExpressPCB and will post the results once finished.

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Thanks

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Chris Sentance

The Multi-function Tester (TC-V2.12k) is good for identifying parts, testing to see if they are good, but the transistor and JFET matching function uses too little gate current for most useful matching. Don't get me wrong, it is great unit and will find a lot of use on my bench, but, to really match JFETS or bipolars requires a dedicated test setup as I referred to in the other thread.

Rod Elliot has some good bipolar matching articles

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This page has a slightly different way of matching FETs

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I started "/g/loopantennas/topic/jfet_matcher_using_an_opamp/107470037" and this thread because I suspect anyone trying to build a clone of the newest Wellbrook loop would do well to match the JFETs. The Wellbrook loop is just a bit out of my comfort zone, I hate winding and trying to phase small transformers, I always turn an amplifier into a not so nice oscillator.

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A lifetime ago I cloned the MXR-90 for a friend and learned "ya really got to match those fets!" the hard way...

Note: Phasing is not the same as flanging. Solid state flanging requires analog delay lines or going full A to D and doing it all in DSP. While I play acoustic guitar, most of my musician friends at least own an electric guitar and are interested in various effects and I often get draggoned in to help.

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I got this one;

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No case but uses a real Atmel Chip. I use it all the time. When salvaging parts from old equipment

no need to identify just plug it in and it will tell you what it is!?

I think Ethernet has great promise because of the tight twist. I did some ingress tests at a site roughly in the center of a triangle of all the Lexington MW stations and Ethernet was almost as good as coax. I suspect I needed better matching then my partner in RF experiments died and I had knee surgery.

Jeff Greene passed away from a massive stroke, too bad he was a great partner for any RF experiment.

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I'll join the CCW group in a few minutes. The good news is my left knee upper and lower parts are in good shape for the replacement to anchor.?

We went swimming after I was zapped, my wife teased me that she'll be able to see me in the dark.

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I'll risk it later today. I have to go in for detailed X-rays so they can pick the best fitting replacement joint.

It sounds horrible but my right knee is so much better words fail me.

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A local civil engineer sued a client who decided to make changes a decade later. It was a bit local mess and I've been leery of letting engineers know I'm modifying their product. I was/am concerned he will take exception to me giving up on the Ethernet feedline.

I think Ethernet has a lot of promise and might actually be better, but, given the near impossibility of meeting the requirements of the National Electric Code, I've decided to toss in the towel and go legal.

Up until now I had his head outside, fed the coax outputs back in but it was always a kludge. This will be a cleaner installation that will make the landlord happier.

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