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FDM-DUO with low power drive BLF188 / eb104 solid state type amplifer? #fdm-duo #eladduo


Christoph K. Schweiger
 

Hello,

I know that some have modified the input for the Ameritron ALS-600 but was wondering if there are any FDM-DUO users out there who can share their experience using other eb104 type amplifiers with low input drive?

Any feedback would be greatly appreciated.

Thanks,
Chris, NE7EE


Simon
 

Hi

I have..

I have a blf188xr amp setup for 100w in..( yeasu driver.) homebrew..based on eb104 modules.

All i did to use on duo was have added seperate tx in connector for the duo( or Hermes lite 2 . sma. So no mistakes.)

Added a switch to toggle between 100w in and 8w in .
The switch shorts out the 10db 100w pad and switches between the rf inputs.
I used relays to do this..

Depending upon what you have will depend upon output power from amp..best i get is 600w..

This is because of the 7db attenuator built into the protection unit..( eb104.)


I am in process of building a 100w amp for the duo..this is to drive the blf188xr amp to 1kw and also the homebrew 1.5kw ussr triode amp..( but then will use the 100w in on blf188xr amp.)

Ask for more information..Simon


bill steffey NY9H
 

I know that  Reinhard DH3NAB at RF Kit uses his FDM Duo driving the RF Kit dual blf 188 amplifier....one of several exciters...

https://www.dxengineering.com/parts/rfk-rf2k-s-kt

just starting to ship as a kit from DXE


bill

On 7/7/2020 3:01 PM, Simon wrote:
Hi

I have..

I have a blf188xr amp setup for 100w in..( yeasu driver.) homebrew..based on eb104 modules.

All i did to use on duo was have added seperate tx in connector for the duo( or Hermes lite 2 . sma. So no mistakes.)

Added a switch to toggle between 100w in and 8w in .
The switch shorts out the 10db 100w pad and switches between the rf inputs.
I used relays to do this..

Depending upon what you have will depend upon output power from amp..best i get is 600w..

This is because of the 7db attenuator built into the protection unit..( eb104.)


I am in process of building a 100w amp for the duo..this is to drive the blf188xr amp to 1kw and also the homebrew 1.5kw ussr triode amp..( but then will use the 100w in on blf188xr amp.)

Ask for more information..Simon
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Simon
 

Hi Chris

More info on what you have ( eb104...blf188xr) type amp would be helpful..

Regards..


Marko Myllymaki
 

I'm using FDM-Duo with Juma PA1000.  Mostly with FT8 at 700 W out with reduced voltage 50 volts on LDMOS 1x BLF188.  If I put normal LDMOS voltage 55 volts (it is menu selection in amplifier), then can get 900W-1kW out on CW with FDM-Duo drive.  Take a look at specs, it is very small and light, ideal for DX peditions or travel.  Bit pricey and noisy, but you can also remote it and have it at distance if noise is problem.  http://www.jumaradio.com/juma-pa1000/

I also have RF-Kit2k+ with 2x BLF189 and it would work too but usually I have it on my K3 radio, so have not operated very much it with FDM-Duo.  With 13 dB pad I have in it it would not give me full legal power on all bands like 15m and up, but probably on lower bands it will get full legal power out with drive levels of FDM-Duo.  And internal pad could be changed to 10 dB or something like that.  RF-Kit that DX Engineering is selling will probably have bigger pad in it and will require more drive.  
73 de Marko N5ZO