That is true, and it is why once I have tuned the transmatch to the frequency using the basic radio, I tune the amplifier and then tune the rig to the amplifier input. The TL-922A input circuits are not the problem. Once everything is tuned, the rig will put 70 to 100 watts to the amp, and the amp will deliver 1 kW to the feed line.


From the other posts here, that's probably because there is not enough room in the case.


Very true. I think I put out 1 1/4 k$ for mine.


That's not a bad idea, but I'll probably invest the $$ in the parts for a home-brew, solid-state amp built around the CCI 347 board.

vy 73 Paul
[/quote]

More than 30 years ago, I built the W1ICP (Lewis McCoy) designed Ultimate Transmatch that was featured in the July 1970 QST magazine. It's a rugged unit with 5 kV variable capacitors and a roller inductor that will damn near match anything from a coat hanger to a mile long random wire from 80m through the 10m band.

That still does not solve the problems inherent with a tank circuit in the amp that cannot be tuned to resonance.

73s de Bob NT0A

Well, mechanically it doesn't sound as if it is possible. I've looked at the schematics, but I haven't popped the hood and dropped the oil pan to go exploring.


Some MARS frequencies are close to the legacy ham bands, but many are not. The TL-922A design allows the amp to tune roughly 500 kHz above and below each of the legacy ham bands, but many of the MARS frequencies are much further away than that from the band edges. Here are some approximate examples:

2.6 MHz
5.8 MHz
9.3 MHz
12.1 MHz
16.2 MHz
Etc.


I will probably build one from scratch using the Communications Concepts AR347 assembly. That will cover the entire range from 2 MHz to 50 MHz.

Has anyone every heard of a modifying the Kenwood TL-922A by putting a roller inductor in place of the tapped tank coil? The amp is a real rugged beast of an HF amplifier, but I cannot use it on MARS frequencies where 100 watts just will not do the job.

73s de Bob NT0A

That's a good amp, but unfortunately it is not a legal (US/FCC) limit amp.

73s es tnx for the reply de Bob NT0A

I am looking for a recommendation for an HF amplifier capable of transmitting on any frequency from 1.8 MHz up 30.0 MHz without manually switching bands. Ideally the amplifier would put out full key down power for all modes including the more robust digital signals for extended periods of time. Obviously the amp should capable of being throttled back for operations that do not require full power.

The bar is now open for suggestions . . .

True.

Great idea, but nothing showed up on a scan around 2.4GHz. Doesn't mean there wasn't something there when I was not scanning, however. Franky, I suspect that some sort of interference on the low end of the band was the root cause.

Now, inSSIDer.exe shows that the signal spans channels 4 through 12 rather than 1 through 9.

FWIW, Here's another reason that I have reserved:

    5. Shit happens!

Don't you just love it when a problem solves itself, but you don't have a clue how or why? Only thing I did was manually switch from channel 1 to a higher channel (10) on the router. Whether that solution works for all times remains to be seen.

Ironically, nothing happened for the better until the entire Time-Warner Cable for my area went tits up. Once it was fixed, the Internet speed in the shack shot up. Why it didn't happen as soon as I made the channel change is anyone's guess.

Anyone want to guess? I have reserved the following answers for myself:

    1. Happenstance.

    2. Coincidence.

    3. Just because.

    4. Blind assed luck.

73s es tnx for the help de Bob NT0A

Perhaps some of you recall my saga with eliminating externally generated RFI from the shack about a year ago. I was successful in killing the spurious RF radiation from the cable connecting the Time-Warner cable modem from my WIFI, but I have struggled with a WIFI problem for months without much luck. As I sit here at my desk three feet from the WIFI router, the download speed is 22.55 Mbps. In the living room with the laptop is slips to 19 to 20 Mbps, and in the bedroom 15 to 18 Mbps. Downstairs in the ham shack, however, it drops to less than 0.5 Mbps.

Obviously the simple solution would be to add a second router or extender in the basement and hard wire it to the source in the computer room. Unfortunately, as previously reported, the CAT5 and CAT6 cables put out tons of RF that ruins HF radio reception on the ham bands. I had to reduce the effective length of a 25 foot CAT6 cable to two feet by wrapping it around four toroids. That is the only cable in the network and it goes from the cable modem to the WIFI router.

I've installed repeaters or extenders, but that does not seem to help very much. I am wide open to any and all suggestions except moving the ham shack yet again.

Power poles, yest works fine. RG-174 no.

73 de Bob NT0A

Yes, there are dies and compression sleeves for 14 AWG wire.

Copperweld is a brand name for a stranded, copper clad steel wire. I used the brand name "Copperweld" because that is what would be recognized. What I am using is a generic copper clad, stranded wire. I apologize if I misled anyone. FWIW, I have used "real" Copperweld wire before, and the generic stuff is just as much of a pain in the butt. as the "real" stuff.

73s de Bob NT0A

I bought the Ultimate Crimp Kit from Quicksilver, and so far it has been excellent, and it costs less than $130.

#14 7 strand twisted Copperweld will take at least 300# before it breaks, so it is absolutely the best if you want to get the antenna a flat as possible. Hindsight is always 20/20, and if I had it to do over, I would have purchased the single strand #12. That wire is less expensive, reportedly easier to work with and has a higher resistance to kinks.


Yes the terminated fan design antenna is a large antenna. The antenna design is based upon a man portable antenna engineered for the U.S. Marine Corps. It's saving grace is that properly designed it has a maximum SWR of roughly 2.0 from 1.8MHz to 30MHz. That's no big deal for the typical ham antenna. With a proper transmatch or tuner, you can use a simple 80m dipole for all the HF bands, but if you operate MARS, you need an antenna that is a broad banded as possible. The primary function of the fan antenna will be for high speed ALE/digital communications on the MARS frequencies.

Of all the NVIS antenna designs that I've found, the terminated fan antenna appears to offer the best performance. Putting it up with the feed point at 30 to 50 AGL, it should offer excellent NVIS performance. Up at 240 feet it should be a long haul band buster across the HF spectrum. I don't have the resources to put it up that high, but I'd sure like to see someone do it and test the hell out of it.

73 es tnx de Bob NT0A