Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: An amp behind an amp??  (Read 1224 times)
W4HIJ
Member

Posts: 367




Ignore
« on: June 29, 2011, 01:39:36 PM »

I have a Flex 1500 as my main radio. Yes, I know it's QRP but it's the best " bang for buck" I can afford right now and I absolutely love it's RX performance. I have built a small solid state amp that runs anywhere from 30 to 50 watts depending on the band when driven with the 5 watts from the rig. I may have some spending cash coming my way and I've been thinking about possibly getting an AL-811 to go with what I already have so I would have extra power when I need it.  Anyone see any issues with daisy chaining two amps behind the rig like this? I'm working on the rig doing automatic band switching on the little amp so it's almost like I would just have a 50 watt transceiver driving the 811.
 Please no suggestions of getting another rig, I don't want anything but an SDR and the next Flex up is out of my price range. I just need to know if my plan is feasible and if there are any major "gotchas" I need to worry about.
Tnx and 73,
Michael, W4HIJ
Logged
W8JI
Member

Posts: 9296


WWW

Ignore
« Reply #1 on: June 29, 2011, 02:51:13 PM »

Every radio is a series of amps behind amps. The only problem is distortion sometimes is much worse with two amps in tandem then one alone, or it can even reduce distortion if the distortin from each subtracts. :-)

As a general rule if the solid state amp you have is more than 5-10 dB better than the AL811 or your radio, it will have negligable impact.

I just measured an AL811, and at 200 watts per tube PEP output the peak distortion products were about 35 dB weaker on normal voice. This data was from peaks stored over a two minute period.

There probably is no harm at all if the solid state amp is pretty clean for odd-order IM.
Logged
AI7RR
Member

Posts: 164




Ignore
« Reply #2 on: July 06, 2011, 02:29:03 PM »

I have a friend doing exactly what you want to do using the Flex1500 and it works just fine. Just do a little experimenting and find the sweet spot for driving the big amp. Also, make sure the impedance is a good match between all units.

73,Roger
Logged
W8JI
Member

Posts: 9296


WWW

Ignore
« Reply #3 on: July 07, 2011, 04:01:21 AM »

Any working amplifier will appear to work.

How it ACTUALLY works depends entirely on the perfromance quality of the driver amplifier. :-)
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!