The most common technology for these filters is Surface Acoustic Wave.  Normally, you order 1,000 of them at a time for $200 each.  If you're lucky, you might find a SAW filter company that just happens to have a pre-designed model in stock, and they're willing to "sample" it to you.

The ham-grade transmitters, such as made by "PC Electronics" have pretty sloppy LC filters that do a poor job- but as good as one can get without spending a whole lot of money.

If you really want near broadcast-grade video, your best bet is to purchase a surplus CATV modulator at a flea market somewhere, and it will already have a VSB filter in it.  Most likely, it will generate the TV signal at the usual IF frequency (41 MHz? 45 MHz? I forget), and youll have to build an up-converter to get it on whatever channel you desire.

AM

I've done plenty of DX and even turned in competitive scores in contests by using a vertical sitting on as few as two radials, less than 0.05 wavelength long.  More land, and more radials is better, but if you can get only one radial planted, then it's a lot better than none.

I've even done well by using soft-drawn 1/2" copper tubing, pushed up through a central chimney (used for routing a PVC furnace exhaust pipe) about 25 feet high - then "planting" radials by stapling them under the floor joists.  In fact, that was a killer antenna on 40 meter DX, requiring only moderate tuning since it was close to 1/4 wave long.

Your situation is not really all that limiting.

AM

I've done it, my children have done it, and my grandchildren have done it.

If you're on the ground floor, tie in to a downspout.  Use black insulated hookup wire.  Run another wire along the base of the building as a counterpoise.  A vertical downspout will run circles around anything indoor any day, unless you're lucky enough to be on the tenth floor of a ten floor building.

I've done this recently from a hotel room on the bottom floor.

With a little care, the installation is completely invisible.

AM

From one of the tube database web sites, make sure to check the dimensions.  Sometimes, the difference between a "plain" and "A" version was the glass envelope.  Drake was notorious at making the chassis barely large enough to fit the tubes they specified.

AM

I disagree with N7DM, and the evidence comes from his own locality.  There are several very loud DXers who live only a few miles from him that use verticals.  They do just fine; I find myself in competition with them in pileups frequently, and they often win.

Those who think verticals are poor performers have made one of two errors:

1) Inadequate counterpoise system

2) Incorrectly expected the vertical to be a good general-purpose antenna.  It's not.  It's a DX antenna.

When you first put up a vertical, and scan across the bands, you think it's doing a bad job, because you don't hear as many strong signals.  The low-angle pattern of a vertical makes it primarily a DX antenna.  It does not hear stateside stations well, and they won't hear you as well.  What it does hear well is DX - but DX is still weaker than stateside.

Per N7DM, a valley should be a terrible spot for a vertical, but I've done better DX on a vertical from a valley than I've done on a low Yagi.

Mainly I use monoband verticals.  I've had a Butternut, and thought it was a very good design, with minimal compromises, for a multi-band antenna.  I've not tried other multi-band verticals.

One of my colleagues just replaced a Gap with a Butternut and said he wished he'd done it long before.  Even without radials, he said the Butternut did better than the Gap.  He's now added radials and is working all sorts of new countries.

GL,

AM

Job,

You're within spitting distance of an HRO.  They've got a store down there on Iliff Avenue in Denver.  Call them at 303-745-7394 - a local phone call for you - get directions and store hours, and go down there.  Do NOT buy your first rig mail order.

By going to the store, you'll meet some great hams, with lots of gear experience.  Often, if you're a newly licensed ham, a nice guy, and it's your first rig, the in-store guys will cut you a special deal that you'll never get over the phone or internet.

You're not going to find dealers that'll save you much more than $20 on a simple tri-band HT anyway.

But right now, as a newcomer, you have to meet active hams.  The guys at the store can give you the skinny on which local repeaters have what kind of users, and what are the featured activities of the various local clubs.

Speaking of local clubs and hams, you MUST contact Howard ("Rip") Van Winkle, NV0M, who lives in your town.  Rip knows everything and everybody and can give you an incredible amount of help getting your station going.  His XYL, Ellie, is an equal contributor to ham radio knowledge.

Welcome to a great hobby, now go out there and MEET HAMS!

AM

There's no such thing as a constant impedance connector.  There are plenty of controlled impedance connectors.

BFH, if you doubt the 900 MHz comment, then you evidently have never bothered measuring the actual loss of cascaded connectors.

In order for a non-controlled impedance connector to cause a problem, it has to not only be the wrong (e.g. non-50 ohm) impedance, but it also has to have a substantial electrical length.  900 MHz has a 33cm wavelength.  The physically short length of a PL-259/SO-239 combination does present an impedance bump that's measurable with a TDR system - but has less than 0.05dB loss at 900MHz.

I once stacked together all the connector adapters I could find in my lab.  I had, ultimately, about eight inches of adapters, maybe a dozen total parts.  My metrology grade equipment (NIST six-port) could measure the imperfections at 1 MHz.  When reality was applied, however, the whole network didn't reach 0.1dB loss until well above 2GHz.  There were plenty of "UHF", BNC and other poorly-controlled connectors in the stack.

AM

It's a matter of philosophy.  Those who use "block" typing are taking control of how text is displayed.

The philosophy of the web, however, is that the reader is supposed to be given maximal control over how a thing is viewed and looks.  Therefore, I never use a carriage return to adjust line length - that is supposed to be something you let the reader control.

AM

I admit that my "baloney alert" starts sounding when a person's claims of antenna performance are based on what some other station told them.

In my many years on the air, I have frequently been told that "You've got the loudest signal on the band!" or "You're the only signal I can hear" or ... and so on.  Sometimes, I was running 5 watts to indoor dipoles or slinkies!  

The propagation link from one station to another contains an untold number of variables, and the antenna is only one of them.  It's not at all uncommon for what you might think would be a lousy antenna to be "the one" that makes the link today, whereas a supposedly better antenna can't muster it.  That's one reason why the top DXers and contesters have identical antennas at many heights on a tower - the highest one is not always best, even though it can be demonstrated (by modeling AND measurement) that it will have the lowest take-off angle and usually the highest gain.

I've done a few rhombics over the years.  I never modeled any of them.  What W8JI said is about what I experienced.  The best of my rhombics was never more than merely competitive with about a 4-6 element Yagi, and they sure did take up a lot of space.

I had the luxury (no longer) of owning 20 adjacent sections in Nevada, so I could erect one antenna for testing in one section, and have over 1000 feet of separation to the comparison antenna.

As has been pointed out, if you really could get 30dBd (or even 30dBd) gain from an HF antenna, you could then not hold it steady enough to keep the main lobe on a station.

For me, the rhomic takes up more space than an equivalent-performing (set of) Yagis and is simply too difficult to rotate.

AM

If your antenna is indoors, you needn't worry about a ground at all.

If it's not indoors, you need to tell us what kind of antenna you're using, before we can provide intelligent info about whether you need a ground at all.

AM

To be legal, the "/" character may only be used to indicate a temporary alteration of something that your license specifies.  Most commonly, it either means a temporary change of location from that printed on your license (e.g. W1AW/6) or a temporary usage of privileges beyond what's printed on the license (e.g. WN1AW/AE if you're a novice who passed Extra but have not yet received the new bit of paper).

The FCC no longer requires the "/" sign for mobile/portable, but many stations choose to use it.  The FCC has not yet opined on whether it is legal to use the "/" character for such non-license issues as QRP.  

AM

K5DVW, your assessment is incorrect.  On the IC-706, you are not hearing IMD/BDR problems.  You're hearing horrible phase noise.  The 706, an offshoot of the 735, has about the worse phase noise of any radio made.

An IMD problem would require TWO close undesired signals, that mix and generate a very audible mess on your intended frequency.  Being merely close to another station, and hearing what sounds like "hiss", is phase noise.

WIK made an exceptionally good observation above.  Get a Kenwood TS-850SAT - $700 and you get IMD/BDR about as good as a modern FT-1000, and dual-slope IF tuning as well.  The Icom IC-765 is another under-$1000 radio with specs as good as the Kenwood, and better reliability (the TS-850 has a known $300 repair - it has either had it, or it's going to).

73,

AM

I've seen them somewhere, just don't remember where.

I have a lightweight flannel blanket that I use to cover the entire station.  I want everything to stay clean, not just the paddle.

AM

The two tubes are exactly the same physical dimensions, and have exactly the same internal structures.  The ceramic insulator on the "P" version is longer, and the anode mounting structure is slightly shorter, so that the overall length is the same.

Capacitances don't matter - you're going to put them in parallel, so the anode-to-grid, or cathode-to-grid capacitance of the paralleled pair is simply the sum of the two.

"Matched pairs" are matched in terms of the required grid bias voltage, and the mu, nothing else.

Most likely, they'll work just fine in parallel.

AM

The best G5RV is the one you build yourself.

All wire antennas are compromises, one way or another.  The first one you put up will never be the one that gives you the performance you want.  If you waste your money on purchasing one commercially, then you'll never have the ambition to replace it with another, because you'll be afraid of having "wasted" your money.

The whole point of wire antennas is to build them, experiment, fiddle, futz, move, change and learn something.

You will not learn anything notable if you buy it.

AM