SABERS!!!
Analog Saber with SecureNet.
According to the RSS R07.01.00, you have to go to the options F4 Change Create View then F4 Radio Feature Options. Then select an MDC 600 option such as H958, H961, H963 or H923. If you have MDC1200 already set you will get a warning. (edit: Motorola issued later CORE firmware like 6D and 7D that might have different or less signalling features)
I don't have a Securenet analog saber code plug, as most of mine are System Saber which is different RSS, so can't say if those options exist same way in your codeplug, but that would be where you would set it.
By the way, there is a note somewhere that if "a channel has MDC turned on", you won't be able to adjust the Deviation Balance (20 Hz and 1000 Hz at 350 mv rms at the aux port) in the service menu. I am retuning a bunch of my radios for Securenet DES-XL and ran into, on my second radio where I think this is happening, no tones were transmitted using the aux port on the test cable. I found a work around (adjust the DEV BAL value up or down). Weirdly I don't have MDC turned on in the radio, but maybe one of the unneeded OTAR features is fooling the process. I am still on the learning curve on this as it has been years since I have dug deeper than setting power or adjusting the reference oscillators. If you do the DEV BAL, beware if your test set has a LPF setting turned on as the 20 Hz tone won't show in the deviation or on the scope. I have an HP8920B and it is loaded with options, some of which will trip you up.
I rebuilt two battery packs and a pocket charger so that my radio would run on rwo cell Tenergy 8.4 V 2200 maH lithium ion batteries Part number 31003. I am not going back to NIMH. These can sit around charged forever and they are ready to go.
Who is using MDC600 these days?