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Entry  Fri Sep 2 13:12:08 2011, kiwamu, Update, IOO, triple resonant box : ready to install refl_eom.png
    Reply  Fri Sep 2 15:56:32 2011, Koji, Update, IOO, triple resonant box : ready to install 
       Reply  Sat Sep 3 14:47:50 2011, kiwamu, Update, IOO, triple resonant box : brief estimations about reflections and mode. depths 
          Reply  Wed Sep 7 22:17:04 2011, rana, Update, IOO, RF Amp for EOM on PSL Table 
             Reply  Fri Sep 9 19:15:17 2011, rana, Update, IOO, RF Amp for EOM on PSL Table 
Message ID: 5339     Entry time: Sat Sep 3 14:47:50 2011     In reply to: 5336     Reply to this: 5364
Author: kiwamu 
Type: Update 
Category: IOO 
Subject: triple resonant box : brief estimations about reflections and mode. depths 

(RF reflections)

The reflected RF power going back to the RF generation box will be :

    Power at 11MHz =  2 dBm

   Power at 29.5 MHz = 3 dBm

   Power at 55 MHz = 9dBm

Assuming the input power at 11 and 55 MHz are at 27 dBm (40m wiki page). And 15 dBm for 29.5 MHz.

Since there is an RF combiner in between the generation box and the resonant box, it reduces the reflections by an additional factor of 10 dB (#4517)

In the estimation above, the reduction due to the RF combiner was taken into account.

 

(Modulation depths)

Besides the reflection issue, the circuit meets a rough requirement of 200 mrad at 11 and 55 MHz.

For the 29.5 MHz modulation, the depth will be reduced approximately by a factor of 2, which I don't think it's a significant issue.

So the modulation depths should be okay.

Assuming the performance of the resonant circuit remains the same (#2586), the modulation depths will be :

      Mod. depth at 11 MHz =  280 mrad

      Mod. depth at 29.5 MHz = 4 mrad (This is about half of the current modulation depth)

      Mod. depth at 55 MHz = 250 mrad

 

Quote from #5336

What are the reflected RF powers for those frequencies? 
Is the 29.5MHz more problem than the 55MHz, considering the required modulation depth?

 

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