12oct16: 8MHz testig
What we did:
- set mesh to 5 MHz ref position
- select 8MHz 8.175 MHz freq
- using phase from 29sep16 rhcp file.
- try to bring all 6 tx up together
- record drive,fwd,reverse powers while doing this
- tx 1,2 tripped reverse power around 35 KW.
- see how reflected power changes as we move the mesh down
- reference position .. recorded values
- 5 feet down .. recorded values
- 10 feet down
- At 10 feet down try to come up to full power all 6 tx.
- Measure/adjust phases lcp,rcp at 10 feet down ->
rhcp_8mhz_161012_low10ft.hfsynth (and lhcp).
- Mesh 10 feet down. use rhcp 10ftlow phases
- see how reflected power changes as we change the frequency:
- move mesh to 15 feet below 5 MHz reference.
- try seeing how high power would go...
- got to 330 KW total
- tx 6 has trouble.. fwd power meter reads too high..limits
how high we can bring it
Summary plots of the day
- Page 1: morning
- Page 2: afternoon
- Page 3: blowup of morning showing tx 4 drifting while drive
- fit reverse power for each tx:
- rvsPwr_i=c0 + c1* fwdPwr_i + sum(j=0..5,j!=i,
- plot rvs power as we changed the frequency
- plot rvs power vs mesh height
- flag when changes were made on plots.. (rcp,lcp, freq
Problems we found:
- Forward power meter tx 6 reads higher than the value from the
coupler by up to 30 KW.
- This could be a calibration problem.. But we also saw large
harmonics on tx6 ...
- Tx4 output power drifts down by 30% in 20 minutes.
- The reverse power trip points have been set to 7.5 KW.
- this makes it hard to test the 8MHz system because of the
- It would be nice if it was possible to raise the trips
points back up to 10KW
(where they were before the change).
- With the mesh at the 5MHz reference position, we can't bring
the 8MHz system up beyond 35 KW.
- We get reverse power trips. This is coming from dipole
coupling, not bad individual vswr's on a dipole
- Lowering the mesh 15 feet (linear on the cable, not
vertical) rcp gave us:
- tx1 - 73 KW
- tx2 - 75 KW
- tx3 - 63 KW
- tx4 - 44 KW
- tx5 - 64 KW
- tx6 - 28 KW (meter was reading 86 KW)
- We tried lcp.. this gave lower rvs power than rcp.
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