illegal amps ???

[cyclops1970]

I heard that some hams run in excess of 10k up on 160m. is that true???

I have also heard my elmer say that he blew up a 5kW slug in a Bird wattmeter one night...and set his curtains on fire at the same time.

Now is the story true? Probably not completely. Is there a grain of truth to it? Probably so. Ham radio is like fishing and most other endeavors in life...the tales grow taller as time passes.

QRN, I'm not on a rant about you personally...it's just that I get ticked off by people who want to restrict what I legally do to prevent nutjobs from doing what they do. We have legislated to death here in the US (you can't smoke, have to wear a seatbelt, can't use certain words, etc.) and whole basis of this is to prevent the one-tenth of one percent of the population from doing what they are going to do anyway.

I don't buy into that philosophy.

And yes, the amp is homebrew...I'm not the original builder however (second owner). It's got two 4-440's cathode driven (I was mistaken--it's only a 4.3 kV plate transformer). Here's the builders original hand-drawn schematic:

http://www.albe24.com/4_400_cr.jpg

There's been additions to the amp over the years such as a bias supply that aren't reflected on the schematic, so it's real interesting sometimes to look inside the amp. Would you believe I got the amp, power supply, transfer switch, and a boxfull of spare 4-400's and 4-250s for $80??

 

[dudmuck]

I heard that some hams run in excess of 10k up on 160m. is that true???

I would think it would be.

Of all the amateur rules violations i've seen, i've never see one citing solely on the use of power greater than regulations allow. There might of been warnings against running excessive power, but its always been in warnings of malicious interference or some such.

The difference between 1,500 watts and 10,000 watts is slightly over one S-unit, or 8dB. Such a difference could easily be lost in skip fading.

Add that, 160 meters is just like the AM broadcast band, where daytime D-layer absorbtion makes the band useless during the day. Antenna efficiency is difficult at such a long wavelength. Because of the size required.. with a compromise antenna the ERP is less, making it look like less power. Antennas too close to the ground become "cloud burners", radiating much of their power straight up.

 

[Captain Kilowatt]

There's been additions to the amp over the years such as a bias supply that aren't reflected on the schematic, so it's real interesting sometimes to look inside the amp. Would you believe I got the amp, power supply, transfer switch, and a boxfull of spare 4-400's and 4-250s for $80??

$80! I will try and refrain from calling you a theif and just call you one lucky SOB instead. Not a bad deal indeed. (This coming from a guy that was given a complete RCA 1Kw broadcast transmitter) :roll: At least you have multi band capability whereas I have only mono band operations and that is still not completed. For some reason the TX has developed a short that keeps tripping the plate supply. Nasties happen when that 3100 volts goes to ground.I gave up on it for a while due to lack of time but I hope to get back at it over the winter. For now I just putt along with my little PW DX-60.

 

[cyclops1970]

I will try and refrain from calling you a theif and just call you one lucky SOB instead.

You wasn't the person who had to haul it home!!!

The builder and original owner put it up on eBay because he "just had too many projects laying around". The only condition was "you win it, you pick it up". I drove about 175 miles to pick it up. It took 3 of us to load the power supply..it runs about 200 to 250 pounds and is mounted on casters. :shock: The whole thing is built like an old Henry floor console model...rf deck on top and power supply on the bottom. Probably 3 1/2 feet high, 18 inches wide and 3 1/2 feet deep (it has a huge Dayton blower on the back for cooling)

It's all band...got additional loading that can be switched in for 160...fully adjustable plate and filament voltage from the front panel (both independently metered as well), in other words a real horse of an amp.

Like I said, I really don't know how much it will put out...but then again...as long it will run 200-300 carrier on AM and 800-1000 on SSB, I really don't care...that's the sweet spot I was aiming for...

I'll have to post pics of it one of these days...it's quite a sight!!!

 

[Captain Kilowatt]

I have you beat! I had to drive 235 miles one way and picked up a TX that weighed in at a bit over 900 pounds.It is approx. 2 feet wide by 3 feet deep by 6 1/2 feet high and then I had to get it down into my basement. I may have won the battle but I think I still lost if you know what I mean.


Pictures here

 

[davegrantsr]

back to the 2nd post of this thread, if it can operate 10, 11, or 12 meters its illegal , is no longer fully correct. FCC rules change now allows factory installed operation without modification on 10 and 12 meters, with all other rules still intact-minimum drive requirements, 10 db limit, etc.

 

[dudmuck]

back to the 2nd post of this thread, if it can operate 10, 11, or 12 meters its illegal , is no longer fully correct. FCC rules change now allows factory installed operation without modification on 10 and 12 meters, with all other rules still intact-minimum drive requirements, 10 db limit, etc.

97.317 says that in order for an amplifier to qualify for certification, it must have no gain from 26 to 28MHz. 97.315 says that an amplifier manufactured or imported must be certified.

If I want that certified amplifier to operating on 28.01MHz, there probably doesn't exist a filter sharp enough to prevent gain at 27.99MHz, while operation at 28.01MHz is un-affected. This is most likely why many amateur HF amplifiers ship operating only 160 to 15 meters.

ts all kind of silly anyways:
97.317(b)(2): The amplifier can be easily modified to operate on frequencies between 26 MHz and 28 MHz.

Who decides what "easily modified" is.

I am reading at:
http://sujan.hallikainen.org/FCC/FccRules/2007/97/317/

Please quote your source of information.