I recently picked up a Kenwood tkr-840 that's a K1 model. Default band is 450-480Mhz. I want to dial it down for 70cm around 144.620. I already have it programmed to this freq and ready, modified the Hex in the file and it is up an running on this freq. but I need to align the receiver and transmitter. I have never done one like this with the software assisted alignment. been alot of years since I did bench work period.? Does any have a step by step on how to align this beast? I have searched till I am blue in the face to find this info with no luck. I have the service manual and all the data sheets with what to set, just not sure exactly how to do it.?

I have the test equipment required, so that's not an issue. just need a little guidance so I can get this baby on the air. ANy help would be greatly appreciated. I found tons of stuff on the 850 models, just nothing on the 840.?

Thanks

Woody

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Did you mean 444.620? ?144.620 is 2 ?bands below 70cm?

Woody,
This has been discussed before in some detail.
These repeaters work very well in the ham band provided they are not a -2 which is high split (480-520MHz) and the low split -3 which is in "govt. band" (400-430MHz) range will also move "up" to the 440MHz bottom edge somewhat also. You will need to hex edit the file to program frequencies into the 440-449.xxxx portion of the band and may need to adjust the VCO voltage for the radio to go into "lock". Once it goes into lock, adjust the helical resonator sections of which there are two sections, four each "resonators"? to center on your receive frequency. You should obtain at a minimum .4uV sensitivity for better than 12dB SINAD if things are working correctly. There is a way to bypass half of the helicals in the front end (with a mod) if this is a garage repeater but I'd just use all of them for a really robust front end receiver. I have several of these on the air at very congested mountaintop commercial tower RF sites and all of them have been between .25-.4uV sensitivity without any modifications whatsoever. We are located in So. California so our receive frequencies are at the bottom of the 440-445MHz portion of the band (upside down from most) 5MHz farther away and they still receive well for the -1 model.
Rick, w6re

Take your time tuning, it will pay off if you are careful about it.
Here is a link to the post topic of tuning the TKR-840-1 into the UHF ham bands:

/g/rc210/topic/tkr_840_seems_deaf_in_the_ham/20346378?20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,20346378