You can find a copy of the manual here:

http://www.radiowrench.com/sonic/so02199.html

I beleive the owner of that website offers repairs for the amp.

AM

Shuguang is the Chinese manufacturer.  You can purchase them from RF Parts (in which case they are labelled "Taylor") or you can purchase them from Richardson Electronics (in which case they are labelled "National") or you can purchase them from a few other companies, variously labelled "Protek" or "Cetron" or "RCA" or even labels they cannot legally use.  I'm not certain, but I'd bet money that the Penta tubes are from the same factory.

Best evidence suggests that there are only two originating sources for 572Bs: Svetlana and Shuguang.  I'd take Shuguang's from any source available.

Matching should not be necessary - I've never bothered with it for a pair.

AM

Unfortunately, what you REALLY need is a directory that tells you which repeaters are actually used, which ones invite visiting hams to try them, and which ones are openly hostile.

It's been a long time since I've been able to drum up a QSO on a repeater when I'm on a trip.

AM

"Simpler" is not a worthy objective of someone who aspires to be part of a well-honed team of communications experts.

AM

Most 3-500Zs are made in China now.  They've gotten past initial quality issues and are pretty dependable.

However, this may be moot.  My SB-220 happily delivers 1.2kW using tubes with 1967 date codes.  Why worry?

AM

We had a good FD, too.

Strange about your 5 watt experiences, though.  When running 5W, even sometimes to indoor antennas, I have never followed any rules about only calling stations that are mid-scale or higher - the weak ones may be other QRP stations and you MUST get them in the log to gain a competitive score.

Also, I only send the callsign multiple times if the other station asks for a repeat, which, IMO, is perhaps one time in 20.

AM

I don't support any form of "antenna challenged" category.

Two reasons:

1) I've done very well in DX/WPX, etc contests with nothing more than a multi-band vertical and a TS-120S - even recently.  Not #1, but in the top ten, a few times.

2) If you made the mistake of buying into CC&R territory, then you already have to compensate by paying mechanics to fix your own brakes instead of doing so in your driveway.  It's a small matter, then, for you to compensate your hamming by finding a suitable high location to contest from in a portable setup.

There are always solutions - we need not continue to sub-divided things down until we're like the car manufacturers "best car in its class" is always achievable if we define the class to include very few competitors.

AM

No, replacing an 811A with a 572B is not a good idea.  Not only will you not get any more output power, but the 572Bs won't last as long.

572Bs and most other glass tubes require the anodes to run hot (not necessarily red - I haven't seen a graphite anode glow red yet!) in order to continue to have the anodes re-absorb gas molecules.  If you don't get them quite hot on occasion, they won't self-getter, and you'll end up with a tube that likes to arc.

I've worked on three amps that were originally 811As with 572Bs in them that the owner complained about fuse-blowing.  The 572Bs, operating with lower anode voltage and current, did not run hot enough to self-getter.  For the amps I worked on, I simply reconditioned the 572Bs in my own test amplifier, and returned the amp to the owner.  Three amplifiers, same problem, all with 572Bs that were less than two years old.

Don't do it.

AM

The True Leaders are where they have always been.

They are AT THE HOMES of the newcomers, elmering them for real.

The internet has ruined elmering.  Elmering isn't a web site (particularly not one like the Test Bench Elmers, which has too many technical errors for me to ever recommend it to a newcomer), nor is it responses to an emailed inquiry.  Elmering is going to the guy's house, helping him figure out how many guy wires he needs, helping him decide if he can use ladder line or is stuck with coax, advising him which trees will be best for his first 80 meter dipole, adjusting his key/paddle correctly for him, and so forth.

Wayne Green, etc, were just figureheads.  By the time Wayne Green was attempting to promote something, the REAL ELMERS had been doing it for years.

So, you can be a leader also.  It takes three steps...

1 - Turn off the computer
2 - Go to a newcomer's house and stay there until he's made his first HF contact (any mode) on the air.
3 - Go back home, and make more contacts on the air, so that the newcomers have someone experienced to QSO with on the air.


AM

An old friend went SK about ten years ago.  Harry was a special man; he and I used to go out scouting for any sort of metal for antennas.  Abandoned fence wire was a treasure trove in those post-depression years.  If a fence seemed to have become some sort of natural barrier to protect true wildlife from accidental incursion into dangerous man-inhabited territory, Harry insisted that we could not take that wire.

A few years ago, I received a letter from Harry's granddaughter.  It seems that going through granddad's estate materials got her husband, and then her, interested, and they have both gotten their tickets.  What a blessing upon my heart to learn that both of them find homebrewing with tubes, using CW, DXing and contesting to be their highest loves.

Said daughter decided to locate the earliest of Harry's early friends in radio.  To stimulate interest, she had found some of his early QSLs and got a new batch printed to look just like them.  She sent a brief form letter introducing herself, and with a request for "anecdotes and stories" about her grandfather.

I gleefully called her on the phone, and after some ten minutes, we realized that we had met at Harry's funeral.  We have stayed in constant communications since then.

Funny thing, when I looked at that QSL card she provided me from Harry's first logged QSO with me, I realized that Harry and I had NEVER exchanged QSL cards.  So here was my QSL card, from a QSO that took place in 1938.  That's 67 years ago.  Of course, Harry and I had who knows how many years of enjoying each others' company, so who needed a QSL card.

And that, too, is a realization on my part.  I was thinking I had been in the hobby just over 50 years.  When you get old, doing math in your head doesn't happen so quickly any more.

AM

Only if you learn how to spell.

I agree, attendance was down.  I saw a lot of people purchasing more than one entry ticket, to increase their odds of winning prizes, and the Dayton Hamfest people can only count ticket sales - not actual attendance.

It was very easy to get around this year, compared to any in the past ten (but I haven't gone to all of them), easier to find parking than in the past, easier to find a room to stay in, and I never waited in line at any restaurants.  Those are all signs that actual attendance was down by a fair amount.

No blockbuster new products this year, just some with a lot of hoopla but not practically improved.

Like G3RZP, my main reason for going is cameraderies with the other hams I've seen there year after year after year after...

AM

Larger capacitors will cause not only a larger inrush, but if a tube arcs, the larger capacitors increase the risk of damaging the tube's grids, or other components.

Best to stick with something close to the original design value.

Why are you replacing them?  Generally, unless the capacitors are oozing liquid, they don't need to be replaced.  I've measured SB-200s whose HV caps were exhibiting less than half the original capacitance, and the amplifier had a completely hum-free signal on the air.

AM

Cooling problems with the Russian tubes are legendary, for exactly the reason you indicate.

Also, be aware that most of those tubes were intended for class C nonlinear use, despite the "new" datasheets.  they are highly nonlinear, and it is difficult to make them linear without running very high bias.  They splatter.

AM

If your antenna needs a good RF ground to be effective, then this is a very poor ground.

If your goal is lightning safety then it's a good start.

You need to tell us WHY you are planning this ground system.

AM