TS-419A/U calibration

[Al-Quran]

do you know why the 8902A RF Level does not measure the TS-419 attenuator ??

i think its because of the frequency stability of the TS-419 that the measuring reciever (8902A) cant detect it.  can the sensor module that comes with the reciever solve the problem ?

right now i am using the spectrum analyzer to calibrate it, but with a limited sticker +/- 4 dB accuracy and only down to -60 dB.

if i could use the 8902A i'll be able to go down to -127 dB.

[Hoopty]

i think its because of the frequency stability of the TS-419 that the measuring reciever (8902A) cant detect it.  can the sensor module that comes with the reciever solve the problem ?

I'm not familiar with the TS-419A/U, but typically frequency instability will be your problem.  There are some special codes that can help, but it's kind of trial and error, and they don't always do the trick.  I'm sorry that I can't be more specific, but it's been so long since I've had to use them, I've forgotten what they are.

[worksharou]

Yes.   i faced this problem before but also when we use special code like 4.  4 to expand the bandwidth the problem stay. 
because the accuracy of the T.  I is +/- 2dB & i think you use 8563E spectrum which has accuracy +/- 2dB then totaly the T.  I accuracy is +/- 4dB. 
try to use high accuracy attenuator like +/-0.  05 dB or less to take a reference without the attenuator then put the attenuator to note the deviation between the T.  I reading & attenuator . 

[Duckbutta]

I'm not familiar with this particular test set but one method that you could try is signal substitution. Record the power reading of the T.I. at 0 dBm for the test frequency of interest. Then inject a stable signal from a signal generator into the attenuator of the TS-419A/U at the desired frequency and do a Tuned RF Level measurement to measure the attenuator steps on the 8902A. Algebraically add the power reading of the T.I. at 0 dBm to the subsequent attenuation readings for the absolute power levels. Repeat as necessary for all the test frequencies.

The problem that you are experiencing definitely sounds like it is related to the frequency stability of the T.I. If it's too unstable the special functions of the 8902A will be of no use. Using the Sensor Module will not cure this problem because the frequency will be just as unstable when it leaves the sensor as it was when it entered. The only solution that I'm aware of is the signal substitution method I just described. We use this method on the 145 Radar Test Sets and it works well.

Hope this helps. Let us know how you make out.

[flew-da-coup]

I'm not familiar with this particular test set but one method that you could try is signal substitution. Record the power reading of the T.I. at 0 dBm for the test frequency of interest. Then inject a stable signal from a signal generator into the attenuator of the TS-419A/U at the desired frequency and do a Tuned RF Level measurement to measure the attenuator steps on the 8902A. Algebraically add the power reading of the T.I. at 0 dBm to the subsequent attenuation readings for the absolute power levels. Repeat as necessary for all the test frequencies.

The problem that you are experiencing definitely sounds like it is related to the frequency stability of the T.I. If it's too unstable the special functions of the 8902A will be of no use. Using the Sensor Module will not cure this problem because the frequency will be just as unstable when it leaves the sensor as when it entered. The only solution that I'm aware of is the signal substitution method I just described. We use this method on the 145 Radar Test Sets and it works well.

Hope this helps. Let us know how you make out.

You can actually manually program the 0dBm error into the 8902a so you don't have to add or subtract the error at every 10 dB step. If 0dBm is actaully -0.5 you just push the (-) (0) (.) (5) (shift) (ext attn). Just thought I would add to your post. 

[Duckbutta]

Thanks, Coup. That was an oversight on my part.

[flew-da-coup]

Thanks, Coup. That was an oversight on my part.

No problem.

[flew-da-coup]

 If you have an old 1295 laying around you could use that for measuring attenuation with an unstable frequency.