I have a Yaesu Ft 8900R and a Yaesu vx-7r.  I'm unclear on how to use crossband repeat from the VX7 to the 8900 to a repeater. I want to when camping carry the vx7 and use my 8900 as a gateway to a repeater.  Is this possible and if so can anyone help me configure both radios in  simple terms that a newbie can understand?

I have an 8800, and they should be the same.

The directions in the owners manual aren't that good.  

Let's use xmt/rec on vhf as an example.

First, treat your radio as two separate radios.  Set the right side as though you'd be using it for repeater operation, ie; enable ARS, pl tone etc.  Once the right side is set, (Using VHF an example), move over to the left side, use a UHF frequency on simplex and match it w/ your HT.  Open up the menu to the cross band repeat option, then hit the top left volume knob twice.  

I think the biggest thing to remember is the left side it what your coming in on (simplex from your ht).  The right side is what actually transmits and receives.  That's how I got mine to work.

If you have any more ?'s drop a PM.

bigohio

First you need to determine if you want to do full duplex or half duplex

Full duplex= everything from the repeater is received by the mobile, and re-transmitted to the HT, and everything from the HT is received from the mobile and re-transmitted to the repeater.   Pros: can allow more range, if the HT can not "hear" the repeater.   Cons: Much higher battery drain and transmitter load on the mobile radio because it re-transmits EVERYTHING from the repeater.   Also requires the mobile to have an auto I.D. function on to meet the FCC I.D. requirements.

Half duplex= HT receives directly from the repeater, and the mobile essentially "boosts" the HT's transmission by re-transmitting it to the repeater.
Pros: Less load/power drain on the mobile radio, no need for auto I.D.   Cons: doesn't work if the HT can not "hear" the repeater

I'm not familiar with the 8900 so I'm not sure how or if it allows both ways of operating.

The setup is different depending on how you approach it,
For both radios, you will store memories with custom splits, so you need to make sure you know how to do that first.

Here is a good setup example

For my examples I will use a repeater with 145.21(pl 173.8) (144.61 input freq)
and I will use 445.975 as my crossband frequency.   I also use tone/tone squelch on my crossband frequency to prevent stray and spurious signals from transmitting to the repeater, so I will use a 107.2 tone in my example.
Not knowing the specifics of the 8900, I will refer to the repeater side and the HT side... It's up to you and the manual to figure out what needs to be where.

Half duplex:
HT: receive 145.21, Transmit 445.975 pl 107.2
Mobile:  HT side 445.975 tone squelch 107.2;  repeater side 144.61, pl 173.8 (you may be able to just use the repeater normal memory  here, it depends on the radio.

Full duplex
HT 445.975 pl107.2 simplex
Mobile: same as above, but with duplex mode and auto I.D. enabled.

Hope this helps
RB