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ameritron 811-hd
- Thread starter 552fl
- Start date
There is a green wire that has to be removed from the band switch so that it will work on 10 thru 12 meters on the aux setting. After that's done it will work but the output on 10 - 12 meters will be lower than advertised. Just nature of the beast.
Which heathkit? I would rather have the sb220 just because it has 3-500z tubes. The sb1000 has a single 3-500z. Both were designed for the ssb user and the plate transformers will fail if you overwork them on AM. The 811 and 572b aren't much better than sweep tubes. Opinions may vary.
Which heathkit? I would rather have the sb220 just because it has 3-500z tubes. The sb1000 has a single 3-500z. Both were designed for the ssb user and the plate transformers will fail if you overwork them on AM. The 811 and 572b aren't much better than sweep tubes. Opinions may vary.
looks like the sb-220 is the way to go with the 3-500z tubes...will out do the 811-hd by a bunch then ...looking at one on e-bay now...theres two connectors on back what goes where other than antenna input and output...foot pedal on which one? whats the other one for?
Most ham radios have an accessory output that will key the amplifier's relay when the radio's mike is keyed.
The 2517 doesn't have this. There are two basic choices, IMHO.
A footswitch plugged into the "relay" jack will key the amplifier.
Installing a relay in the radio works. We hook the relay to the "counter" jack on the back of the 2517. A patch cord from that jack to the relay jack on the amplifier will now key it whenever the mike is keyed.
We sold a board to install in this radio as a DIY for years. Supply is a bit low at the moment, so I'm sitting on them until we make another batch. Don't want to run out before we can get more of them made.
That one is on the 'old nomad web pages' section of http://www.nomadradio.com
It's not a big deal to build yourself if you're comfortable wiring up parts on a perf board.
73
The 2517 doesn't have this. There are two basic choices, IMHO.
A footswitch plugged into the "relay" jack will key the amplifier.
Installing a relay in the radio works. We hook the relay to the "counter" jack on the back of the 2517. A patch cord from that jack to the relay jack on the amplifier will now key it whenever the mike is keyed.
We sold a board to install in this radio as a DIY for years. Supply is a bit low at the moment, so I'm sitting on them until we make another batch. Don't want to run out before we can get more of them made.
That one is on the 'old nomad web pages' section of http://www.nomadradio.com
It's not a big deal to build yourself if you're comfortable wiring up parts on a perf board.
73
Don't pass up a Drake L4b if you find one. At first I thought you had a 100 watt radio but I confused the 2517 with something else. Most HF amps will need something in the 50 to 100 watt range. You may need a small driver but that's ok. If you turn the radio down and run a 2 pill driver under 100 watts you'll have a cleaner signal than if you tried to put hot rod parts in the radio.
Oh....The relay that keys the ameritron is a 12 volt relay so no real safety precautions there. The heathkit has over 100 volts on the relay so the keep that in mind when you're wiring up a switch to key one. I'm not sure about the voltage on the drake.
I have a one pill and a two pill for drivers...tried bidding on a drake l4b but went up to $1375 only have around $1000 to spend...yhe reason I like the ameritron 811h was its brand new;. how many watts do you lose doing the 10-12 meter mod? looked at pdf manual did not see any about the green wire removal..or do you just cut green wire off the back of band switch???
You don't lose power by doing the modification. The amplifier just has less gain on 10 thru 12 meters. The green wire just shorts the input in the aux setting so it will not amplify the signal you put into it. This video will show you the green wire. Skip ahead to 3:00 if you don't want to watch the whole thing.
$1375 is crazy for an L4B. You can find a used al-82, 1200 or 1500 in that price range. eBay prices on amplifiers are outrageous. You can find better deals looking through ham radio classifieds. An L4b pops up every now and then with an asking price of around $800. With anything this old it would be a good idea to test and replace the electrolytic caps and bleeders for the HV power supply. I'd figure in another 100 bucks for maintenance items after you buy something old.
Shadetree Mechanic
Delaware Base Station 808
800w pep would do it for me. The new Ameritron would seem to be a simple way to get a big amp. I have been looking at the SB220s and buying used equipment is hard if you don't really know what to look for. That keying board that Nomad has is perfect. I hope to get something big by the end of summer.
Chris
Chris
Bear in mind that the Ameritron 811 series amps including the 811H are running the tubes beyond the normal specs. Even Tom Rauch, W8JI, who designed all the amps for Ameritron admits that. The 811 amp is really good for 400-450 watts and the 811H is a nice 600 watt amp but running at 800 watts is really pushing the fragile 811A tubes and that is in SSB service. Start running it in AM service and I want to be your tube supplier.
Here are some guidelines for running common tubes in AM service if you want a clean signal and maximum life from the tube.
https://www.w8ji.com/am_linear_amplifiers.htm
For what an 811h will cost you might be better off with something like a palomar 300a. Sweep tubes are expensive but so are the 811's for what you get. A friend bought an al-572 a few years ago. It's a good amplifier but he is an AM user and is disappointed with it.
Personally, I wouldn't go with anything smaller than a 3-500z. One will cost about the same as 4 811's and be more durable. An al-80b will run 125 watts carrier and 500+ pep easily. They call it a 1kw amp but that's beating the hell out of it on ssb.
https://swap.qth.com/index.php
https://www.w8ji.com/am_linear_amplifiers.htm
For what an 811h will cost you might be better off with something like a palomar 300a. Sweep tubes are expensive but so are the 811's for what you get. A friend bought an al-572 a few years ago. It's a good amplifier but he is an AM user and is disappointed with it.
Personally, I wouldn't go with anything smaller than a 3-500z. One will cost about the same as 4 811's and be more durable. An al-80b will run 125 watts carrier and 500+ pep easily. They call it a 1kw amp but that's beating the hell out of it on ssb.
https://swap.qth.com/index.php