The whole idea of the loading coil is to make the antenna "rfwise longer".  If the coil is a resonator, that is something different.  A resonator for say 40M would form a current stop on 40M on an antenna designed for say 40 and 80M operation.  It would add a certain inductance to the 80M operation.

The loading coil goes in series with the antenna.


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 Feedpoint
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Ground/counterpoise


A coil can also go other places rather than the base.  It may go near the center of the element.

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 Feedpoint
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Ground/counterpoise

In this case the coil would be different as the current/voltage is different that near the base.

Good luck

73, JP, K8AG

3 ohms is a huge problem.  RG8X has a 16AWG center conductor.  16AWG wire has about 4.2 ohms of resistance per 1000 feet.  Yes connectors will insert some resistance, but 3 ohms is a lot unless you are running 500+ feet of the stuff.

Think of it this way, even if your antenna is 50 ohms exactly, through the coax your radio will see 53 ohms.  So roughly 6% of your power will be lost just in that connection.  And this is only DC.  RF will be higher.

I would check to see that all of your connections are not cold solder joints.  I use a soldering gun as it does less damage than an iron.  They get hotter and you can hit n' get without heating up the coax and connector too much.

My 2 cents

73, JP, K8AG

You really want to check this out.  I found out that in my town it is illegal to ride a bicycle in a city park.

I thought that was what parks were for.

73, JP, K8AG

Rather than DevC++ try wxDevC++.

http://wxdsgn.sourceforge.net/

It comes with wxWidgets (used to be wxWindows) so you have a lot of predefined dialogs and such to play with.

73, JP, K8AG

People throw the word signal around without much precision or explanation.  If we assume that we are talking about a bipolar transistor, we need a current in a forward direction in the base/emitter junction to allow a larger current in the collector.  Both base and collector currents flow through the emitter.  But a little current forward through the BE junction allows a lot of current (reduces greatly the resistance to current) through the collector into the emitter.

If you truly understand DC Ohm's Law this will be clearer.  We are talking about currents with a bipolar transistor.  Other transistors use voltage at the low power end to allow current to pass.

Hope this helps some.

73, JP, K8AG

Lots of people, public access, portable equipment all add up to a potential for theft.  I would think that would be a concern.

Just a thought.

73, JP, K8AG

I agree with WIK.  If the dealer has 99.6+ with 100+ sales transactions and the scope actually shows all of the traces showing an active waveform, I might bite if the price was right.  Also make sure that all of the plug-ins displayed come with the unit.  Plug-ins are frequently not tested when sold and you have no clue if they will work.

If you are very very careful you can get a deal.  $200 does not sound like too ridiculous.  After all, service on  these scopes is expensive.  They are 30 year old scopes.

73, JP, K8AG

That's my QSL card!!!!

Everybody on HF is pinging the ionosphere.

73, JP, K8AG

I used to repair and design linear supplies for a living.  Problem might be the pass transistor(s).  Frequently a voltage spike will cause them to short and the output voltage simply goes up to the unregulated value.  Replacing the 723 may or may not solve the problem.

Usually you can check the transistors for a short C to E.  That doesn't guarantee that they are good, but it will show very bad ones.

Your crowbar circuit may also be toast.  It is supposed to clamp your output if it goes too high (so your radio doesn't join the destruct festival).  Sounds like it was trying to do that but if your pass transistors are shorted you can fry the crowbar as well.

Good luck.

73, JP, K8AG

Irregardless, I could care less about spelling good.  Just so long as I don't miss spell on accident.

73, JP, K8AG

Many years ago I had problems with digital meter accuracy.  They have the precision, but not the accuracy to back it up.  The one I was using would not even repeat well.

Also be aware that there is a .1 volt drop from no load to full load as well.  Difficult to regulate any tighter than that.

73, JP, K8AG

If everybody traded your way nobody would trade because nobody would send their gear first.

I require that it be a ham and that they be in all of the databases.  I only ship to the address listed in the databases.  I also check out the call, name, address etc. on the Internet.  If everything checks out I take the plunge.

So far I have no complaints.

73, JP, K8AG

First you really should have a dummy load.  When there is a problem with SWR, you can divide it between the radio and everything else.

Variable power supply is always a good idea. You can make one really cheap nowadays.  0-15V or so, 1Amp should be plenty.  Great for experimentation.

I also recommend a working ugly oscilloscope.  You can get them for pennies on the dollar on Ebay as long as you are careful.

My 2 cents.

73, JP, K8AG

I wouldn't force HF/VHF/UHF into the same box.  Consider buying an inexpensive HF rig (like an ft747gx) and a separate dual bander for VHF/UHF.  You are still looking at close to $500 with both in decent shape.  Maybe push it down to $400 with an older tube HF rig and a dual bander with "appearance problems".

My 2 cents

73, JP, K8AG

I have not yet built it but I am still considering it.

If you accidentally used a 10-ohm resistor for what was supposed to be a 10k you may have taken out an adjacent device (transistor etc.).  Pull any parts electrically near the new 10k and test them.  As I recall the oscillator is a fairly simple pierce design which have always worked pretty well for me.

My 2 cents.

73, JP, K8AG