900 IR Quantars

[WB5ITT]

I picked up 7 900MHZ IRs from a P25 single site trunk system replaced by a Mototurbo system...Want to use them on 902/927. I THINK only one has a 10MHz reference as they were all cabled together via coax to the BNCs on the back...NO external reference I could see (I got EVERYTHING but the trunk controllers)....
There is a UHF Quantro at my rptr tower site with an external GPS driven 10MHz reference I COULD tap onto to use but prefer to use my own/internal ...especially since I intend to sell 5 of the 7 I have....(maybe less....I am working on a 1500ft site and may locate one there).

SO what do I need to do to use this as a 927 rptr?? Do I need to do anything to the SCM or just reprogram the rptr as a CONV in the RSS? Everything I have found so far is confusing and its been YEARS since I touched trunked Quantars (going back to 1996 and the worlds largest SZ system at the time, operated by Entergy) Please be detailed as much as possible...I don't want to make a mistake 😁

I intend to connect it to an external RLC controller but want to get it on air using the internal controller asap. Feedline and antenna already at site. Duplexer made from two Celwave 5044 BP filters...(also called Celwave 5043)

Thanks,

Chris

 

[jeepsandradios]

Read repeater. Check settings. Depending on firmware change to internal reference and repeat mode. Change frequency and PL. Write and Reset.

 

[prcguy]

I would check the model of your Epic card and I believe an Epic IV is for trunking and will not work as a conventional repeater. Otherwise just program and use it. If the old system was analog you will probably have to do an alignment for P25 waveform but its not difficult. Here is some info on hardware part #s and what they do. Quantar - W9CR

I have two 900 Quantars running as dual mode conventional repeaters and both have internal reference cards. I have played with external reference and mine seem to like a sine wave source and had problems locking to a square wave source even though the levels were correct. I found most 800/900 duplexers are designed for a 45MHz split and some don't do amateur 25MHz splits very well. I found a model of Bird-TX/RX Systems duplexer designed for about a 3.6MHz split at 900 and they work really well.

 

[Project25_MASTR]

The BNC with factory T on the back which all of the Quantars should have been cabled together with is 10BASE2 Ethernet IIRC. Been awhile since I've done much with that connection.

 

[WB5ITT]

Well, I guess I was not clear enough....I DONT KNOW which repeater of the 7 has the internal reference.....I thought I made that clear earlier (this was a P25, not analog, single site trunked system at a plant)....The 10BASE2 cable goes from Rptr 5 with no T, thru the other 5, then to rptr 1 which has the T and terminator....so is Rptr 5 the one with the reference?? or is Rptr 1 it??? I guess I need to get 10MHz ref for the others....plenty for sale on EBay, etc...... The two Celwave 5044 filters are also sold as a duplexer (5043)..and can handle the 25Mhz split....at 25MHz, they are 85db down at least......1db insertion loss...just need to make the T cable from antenna to TX and RX side... I just need to make ONE work right now...Guess I'll check the Epic card...is that next to the SCM???

 

[mikewazowski]

Do you have a UHSO module (labelled as REFERENCE) on any of the units? The 10Base2 connections were most likely so the units could talk to each other. Which ports were connected up? Here's a reference: Quantro/Quantar-Backplane - W9CR

The EPIC card is the SCM.

 

[jeepsandradios]

Just read the repeater. Any of them can have internal reference if the card supports it. Until you plug into one with software all folks can do is guess.

 

[prcguy]

Do you have a UHSO module (labelled as REFERENCE) on any of the units? The 10Base2 connections were most likely so the units could talk to each other. Which ports were connected up? Here's a reference: Quantro/Quantar-Backplane - W9CR

The EPIC card is the SCM.

The internal UHSO reference will have some vent holes near the bottom of the front panel to the left of the receiver and if there is no reference module it will be a solid blank panel. Be aware the 900 Quantar with will take about 10 minutes from power on until you can use it, that is to allow the ovenized oscillator to reach temp and get on frequency.

 

[Lucifer_Morningstar]

All Quantars (if pointed to the UHSO FRU) will lose the "exciter" lock LED if the UHSO
is power cycled due to that warm up period (as many a site tech has discovered by
accident when they inadvertently crash the site - fix: blame it on Verizon).

However, if RSS is connected to the host Quantar with the UHSO, you can override
the warmup period - under service > alignment > UHSO

If you can't identify the UHSO (and no reason why you can't - it'll be pretty obvious
as described by others), disconnect the jumpers on the back of each station. If you
lose exciter lock, the stations are expecting that reference.

If there's no UHSO in your Quantars, it was "probably" configured to work off an
external GPS as the reference. Still salvageable though, go into RSS and point them
to their internal references. They're pretty accurate standalone.

If your exciter lock LED's are lit - then it's fine, original question is totally moot.

If you "tap" into someone else's GPS, if it were *my* GPS and I found bootleg taps,
they're getting cut (with extreme prejudice). Had a site owner that would routinely
pull AC power on deadbeat repeater owners.

("what business is bad ? F U pay me !" , "house burned down ? F U pay me !)