Stupid Question: ALS-600 -- Do I need an external antenna tuner?

[K7BB]

So I'm really considering the ALS-600. I've never owned an amplifier before -- I've always operated barefoot 100w on HF. The ALS-600 is in the budget, and I like the fact that it's got lots of fail-safe's built in to prevent an idiot like me from smoking it.

What I can't figure out is if I can use the antenna-tuner built in to my IC-7600 and/or my FT-1000MP -- or if I MUST buy an external antenna tuner to sit between the amp and the antenna. (And if I must... I'd love some suggestions).

Ideally I would just go IC-7600 --> Amplifier --> Antenna but maybe I'm dreaming. =)

Any help would be VERY appreciated.

[N9ZP]

You CAN NOT use the internal antenna tuner in the radio while operating the amp. You will need an external tuner installed as the last thing before the actual antenna. I recommend Palstar, Older Dentrons or Ameritron ATR-30. All legal limit + tuners.

[K7BB]

You CAN NOT use the internal antenna tuner in the radio while operating the amp. You will need an external tuner installed as the last thing before the actual antenna. I recommend Palstar, Older Dentrons or Ameritron ATR-30. All legal limit + tuners.

okay.. that's what I was afraid of. I'll have to wait a little longer until I can afford both pieces. =)

THANK YOU!!!!!!

[W4PG]

What kind of antenna are you running and what is the SWR typically? Transistorized amps tend to start dropping power when the SWR gets to 2:1 and higher. If you can keep the SWR below 2:1, you should be OK. This is why I like resonant antennas!!

..........Bob

[K7BB]

What kind of antenna are you running and what is the SWR typically? Transistorized amps tend to start dropping power when the SWR gets to 2:1 and higher. If you can keep the SWR below 2:1, you should be OK. This is why I like resonant antennas!!

..........Bob

Two antennas I want to hook this to...

First is an 80-meter loop (no idea what my SWR is w/out my tuner. I'll have to check it).

Second is a 5-band spider beam. It should be resonant.

Think I can get away with this amp on the spider-beam w/out the tuner?

[WA7PRC]

Two antennas I want to hook this to...

First is an 80-meter loop (no idea what my SWR is w/out my tuner. I'll have to check it).

Second is a 5-band spider beam. It should be resonant.

Think I can get away with this amp on the spider-beam w/out the tuner?

I use a cage inverted vee on 80m... it's as broad as a barn door. Until I bought my TS-850SAT, I never owned an ATU, and the ATU isn't used. When I was "antenna challenged" and before I had a rig with an ATU built in, I used my SB-220 amplifier as a "buffer". It didn't care what the VSWR was.

[KO6WB]

If the spider beam was tuned when you put it up and the SWR is below 2:1 then the ALS-600 will work directly into the antenna. For an antenna that you can make or presently use the loop with ladder line, there is a method of matching that does not require a tuner. The details for that are presented by W5DXP on his web site; http://www.wadsworthsales.com/Pages/w5dxp.aspx. Perhaps this will give you some ideas.
Hope this helps
73
Gary

[W4PG]

Think I can get away with this amp on the spider-beam w/out the tuner?

As with any antenna, it will depend on the SWR. Get a good SWR meter and check and see. Tuners were never that common until everything went transistorized. As PRC mentioned, tubes are pretty rugged and will work into a high SWR pretty well. Transistors won't!!

You can certainly design many different 80 meter wire antennas that will not need a tuner, though the bandwith (that area between SWR of 2:1, say . . . ) is reduced compared to the higher bands. On 80, I run a simple folded dipole made from 450 ohm twin-lead and fed with 300 ohm twinlead down to a 6:1 balun, then a few feet of 50 ohm coax into the shack. I can run from 3.5 to 3.8 without a tuner. The Wireman sells all the stuff for the antenna including center connectors and end connectors for a few bucks - MUCH less than a tuner!

I would think you could adjust the spider beam so you get resonance or near so on the bands it works, though I have never used that antenna. With some experimenting, you can find out what parts of the band it works on and where to avoid, depending on the SWR. No tuner needed!!

.............Bob

[W9GB]

So I'm really considering the ALS-600. I've never owned an amplifier before -- I've always operated barefoot 100w on HF.
The ALS-600 is in the budget, and I like the fact that it's got lots of fail-safe's built in to prevent an idiot like me from smoking it.

Brian --

The migration to higher RF power is NOT a one purchase (I bought an amplifier) ... solution.

The frequent complaint (comment) from new ALS-600 owners --- they did not fully appreciate (or understand) the specifications they were reading.

1. Your antenna system MUST be 2:1 or lower SWR on your desired frequencies (without a tuner)
AND antenna system (commercial or homemade) rated to handle ~ 600 watts RF.
The whining from first time owners was substantial several years ago, when the ALS-600 was first introduced, who tried to use it on 80 meters with their poor antenna systems.

2. Antenna system upgrades are often required --
OR an antenna tuner rated for 1 kW or greater may require purchase.

3. Your HF transceiver's internal antenna tuner should be turned off, in most circumstances.
Whil useful for 100 watt barefoot HF operations ... it is not used for higher power (amplifier usage).

4. Look carefully at your budget and do some planning ... before spending your $$.

[K7BB]

Thanks everyone.. this was exactly the info I was looking for!!! you guys are great.