Single antenna and bandpass filters on 6600

Logan KE7AZ

The 6700 RF routing diagram in the hardware reference manual shows that if you have a single antenna, the splitter feeding the SCUs is after the bandpass filter.  I interpret this to mean that if I have a single HF multi-band antenna and I have an SCU with a 20m slice receiver and an SCU with a 40m slice receiver, the band pass filter will be in the "WIDE" mode.  Does the 6600 use the same RF routing scheme?

Asked another way, if I have a single multi-band antenna, can I have a 7th order bandpass filter on each SCU or do I need two separate antennas?

Logan, KZ6O

Tim - W4TME

Each SCU module has it's own bandpass filters (preselectors).

An SCU is connected to an antenna.  If you have two panadapters that do not exceed the bandwidth of a band, a slice in each panadapter and each slice RX is on a different antenna port, then each antenna is on a separate SCU and the preselectors for that band will be enabled.

I do this all the time when operating 6m and HF.  My 6m beam is on ANT-2 and I have a 6m panadapter open with a slice in it.  For HF, my multi-band delta loop is connected to ANT-1 and I use a different panadapter and slice receiver for it.  And the preselectors are enabled for each SCU (panadapter/Antenna combination)

Also, the 6700 does not have 7th order preselectors, only third-order.

Logan KE7AZ

I'm sorry but I don't fully understand your answer, so to be clear, I made two diagrams of possible arrangements.  Switching A is the arrangement in the 6700.  Switching B is an alternative.  Which diagram represents the switching arrangement in the 6600?

Tim - W4TME

It is a lot more complex that that.  The SCU BPF (preselector) can be switched out of the RF signal path if the bandwidth of the panadapter associated with SCU is greater that the bandwidth of the BPF.

If you have one antenna connected to all panadapters and all slices, then only one SCU is digitizing RF for everything, the signal is not split.  I think this is where your confusion might be coming from.

Logan KE7AZ

Ok, I think I get it.  Based on the last paragraph, if I want to use SCU0 and SCU1 simultaneously, then I need two antennas.

Tim - W4TME

Correct.  In the future, it may be possible to combine both SCUs for an increase in dynamic range, but for now, it is one antenna, one SCU.

Logan KE7AZ

Got it.  And that is one thing that differentiates the 6600 from the 6700, since the 6700 has a splitter for use with a single antenna.  Thanks for the clarification, my question is answered.