High Drive Amps?

[skiman1]

Looking for an amp that I can use with my Yaesu FT-991a and Icom 7200 for 10-11m use. Sadly the Yaesu can't go below a 5 watt carrier (way to much for my 667) and the Icom sounds like ass when run below 3-4 watts, so looking for something I CAN run even a 10-20W carrier into and not blow it up. Any suggestions?

Not much out there comes up when you look for High Drive amps, seems the definition is ALL over the place, especially when looking at Texas Star, thanks!

 

[Shadetree Mechanic]

Heathkit SB220

 

[nomadradio]

To run a radio that size with an amplifier, you really need an amplifier built to match a radio that size.

Pretty much restricts you to the legal-type ham amplifiers built to match the typical 100 to 120-Watt HF transceiver.

Like yours.

73

 

[Mudfoot]

I believe you can go in the service menu and lower wattage.

 

[BJ radionut]

Plus most of the "conventional" CB type amps are good for maybe 12/11/10m...They don't have the bandwidth to run all HF bands.
Plus any Class C type amps are JUNK on SSB.
The newer RM Italy mobile type amps will do all bands, but going from 100watts to 300 watt from those is certainly not worth the price there getting nowadays, except for mobile usage.
Save your money and put up better antennas!
However:
Heathkit SB220...Drake L4/L4B...Kenwood TL922A...or the Ameritron series of HF amps are where you should be looking.
All the Best
Gary

 

[Dmans]

Palomar 300A. Runs 40-10 meters, takes a 100 watt drive in Low power and will net you about 600 out. Expensive upkeep if you snag an abused specimen!

Good Luck!
73's
David

 

[543_Dallas]

The larger Texas star amps will work. The sweet 16 or one of their 8 transistor amps. I wouldn't put a crap CB amp behind a decent radio though.

The drake l4b is nice. Maybe an ameritron al80b. How much power do you want and how much do you want to spend?

Turning down a 100 watt radio and buying a 300 watt amp is a waste of money. JMO

 

[skiman1]

Thanks guys, lots to chew on for sure, time for research!

 

[nomadradio]

Palomar 300A has a three-band selector on the driver and final output circuits.

Has an 11-meter only input circuit.

The band selector is a fraud, and the input-side SWR will be insanely high on the ham bands.

Not such an attractive choice.

73

 

[kopcicle]

 

[Shockwave]

There is another option. You could mount one of these attenuators on the 667 heatsink and inline with the RF drive: https://www.ebay.com/itm/100-Watt-5...2-3-4-6-10-20-or-30-dB-to-2-GHz-/371730637224 Depending on the model and db of attenuation, they can easily reduce a 100 watt drive level down to anything as little as 100mw.

 

[kopcicle]

There is another option. You could mount one of these attenuators on the 667 heatsink and inline with the RF drive: https://www.ebay.com/itm/100-Watt-5...2-3-4-6-10-20-or-30-dB-to-2-GHz-/371730637224 Depending on the model and db of attenuation, they can easily reduce a 100 watt drive level down to anything as little as 100mw.

Seconded...

 

[oldtymer]

Looking for an amp that I can use with my Yaesu FT-991a and Icom 7200 for 10-11m use. Sadly the Yaesu can't go below a 5 watt carrier (way to much for my 667) and the Icom sounds like ass when run below 3-4 watts, so looking for something I CAN run even a 10-20W carrier into and not blow it up. Any suggestions?

Not much out there comes up when you look for High Drive amps, seems the definition is ALL over the place, especially when looking at Texas Star, thanks!

You spent some serious money for those two radios, time to pair them up with an
appropriate stablemate.
Depending what mode you operate on here are a few suggestions.
Set your AM carrier to 10-15 watts on either radio, need some headroom for the audio. On a 3or4 tube 811 you should see 80-120 watt carrier. Plate dissipation for 811 tubes
is 65 watts per tube and they got hot fast on long keydowns.Modulated 400-600 watts
peak depending which model you use.
On SSB about 65 watts of drive should give you 450-650 pep, we are on 10 or 11
meters per your post and you will not get full output on those bands, 20,40, 80 yes
but not on 10 or 11.
With the AL-80B Ameritron recommends 200 watt keydown max on AM.
I have run 10 meter AM with about 150 keydown and 700-750 peak driving it with a
Kenwood TS570 & had a good clean signal with acceptable audio.
You got two good radios there, BJ, Nomad & 543 are giving you good advice.
CB amps are for CB radios, most of them have lousy tuned inputs and could damage
your radios.

 

[nomadradio]

Over four decades now, and I wish I had kept some kind of tally for how many times someone wanted to pair a 'big' radio with a 'too small' amplifier. Comes up a lot.

The motivations for this vary, but it seems that after spending the money for the 'big' radio, the budget for an amplifier gets small. I have always recommended a ten-to-one rule as the minimum power step-up that's worth spending any money.

Not coincidentally, most amplifiers you'll encounter have a gain factor that multiplies the input by a factor of ten or more.

One common exception is the once-popular '1000-Watt' input-power ham amplifiers that used a pair of 572B tubes. Seems like every major brand sold one at one time or another. That design comes in at six or eight-to-one gain factor. A pair of the 3-500Z tubes will show closer to 11 or 12 to one.

Making a "small" amplifier jump through a flaming hoop by inserting an attenuator is an option, but I still fail to see how the benefit this offers can justify the expense.

Just spent too many years focused on making sure a customer gets a bang for his buck, I guess.

73

 

[Shockwave]

The attenuator is only $30 but the more I think about it, the more I would be just bypassing the first driver transistor. Either way it would be equal to the signal increase the ALS-500M gives the typical HF rig. Not much but it is an increase.