I think your notes on how it is hooked are close but not exact( at
least not the way we have done them in the past) . The comp line needs to
be connected inside the element, A 2C effectively needs to be made into a
5C( or better yet use a 5C channel element). The comp line is a dc
controlled varactor tuning stage, consequently it responds nicely to slow
dc changes ( or close coupled DPL or LTR signals) The rest of the modulator
is normal for voice, just the encode portion is routed through the comp
line. No other changes to the exciter are required but to make sure the
comp line is routed from the end panel( preferably on a spare pin) through
to the channel element. There is no need to disconnect the normal comp
functions as the DPL or LTR ( or ctcss for that matter) will superimpose
just fine. You do have to make sure the comp line is not tied to the RX
also however as it would modulate the rx channel element too and really
mess things up on that side.
Doug
KD8B
At 11:21 AM 7/8/2005, you wrote:
>I serviced a Master II UHF Repeater last night,
>has a Com Spec TP-38 tone panel attached.
>
>The transmitter had an interesting mod I've
>never seen. Maybe some of you know about this
>trick? (The original Master II transmitter
>doesn't transmit digital coded squelch well.)
>
>The transmit audio directly drives the pcb trace
>cut loose "Frequency Comp lead/pin", the regular
>tx modulator and limiter stages are not used.
>
>The only other required mod is trace cut inside
>the channel element.
>
>Anyone ever heard of this mod or tried it?
>
>I wouldn't have believed it if I hadn't seen it
>myself. Seemed to work pretty well if you need
>"poor mans dcs" in your Master II.
>
>cheers,
>skipp
>
>
>
>
>
>
>
>Yahoo! Groups Links
>
>
>
>
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