wI0OK/r Glen Arbor - Empire Michigan

444.725 Mhz / 52.92 Mhz

The wI0OK Glen Arbor - Empire repeater provides both UHF and 6mtr coverage to southwest Leelanau, northern Benzie and much of Grand Traverse counties. The repeaters even provide some coverage to Kalkaska, Antrim and Manistee counties.

The 444.725 repeater, with an input on 449.725 (114.8hz PL) is functionally tied together with the 52.92 repeater. The 52.92 repeater has an input on 52.42 and presently does not require a PL tone for access, but may eventually require PL should the situation warrant changing to PL access.

This pair of 'conjoined repeaters' has a remote base transceiver which can operate on a selection of two meter ham frequencies or on 224.56 MHz . When the remote base is in the 224.56 MHz mode, the repeaters are effectively tied to the WB8DEL 224.56 repeater in Stutsmanville MI (near Petoskey).

The summer of 2005 saw the repeater antennas moved up the tower t the 330' level, with a corresponding improvement to the coverage. During 2004, the addition of satellite voting receivers for both 6m and 440, a new control system which gives the machine much greater functionality and flexibility, along with battery backup on 440 and a synthesized 2 meter remote base transceiver. These improvements have provided a reasonable improvement in coverage . I've got a system block diagram showing what's in place.

A blog has been created to keep those of us interested in the repeater up to date on technical issues related to the system. You can view the wI0OK Blog at: http://wi0ok.blogspot.com

	To the left is the view of the 400' tower that primarily holds the antennas for the 95.5 and 98.1 'The Zone' and 'The Bear' FM stations (WJZJ, WGFN) licensed to Glen Arbor. The site is south of Glen Lake and east of Empire and just north of M-72 atop a good sized hill. Also on the tower are two 'cellphone' companies, the county police/fire, and a gas company. This photo was taken before the 'new' repeater antenna was placed at the 330' level on the tower. You can see the remote-base and secondary receiver antennas in this photo, as they are at the 100' level. There is also shown a 220mhz AEA Isopole at the 60' level, that has since been removed and replaced with an M2 yagi.
	This photo shows our antennas on the left, just above the side marker lights, and below the sidearm for one of the cellphone antennas. While it might have been nice to put the antenna at the very top, this location is 'just ducky' as it's not going to be the first thing a lightning strike will want to hit-- and it's at least a few feet away from all that FM broadcast energy. This image is looking west. Below on the left is a closeup showing the six meter DB products folded dipole oriented to the south. It is almost impossible to see the DB products four element UHF folded tipole array in this shot, as that is oriented to the east, in perfect alignment with the mast from my cameras perspective. Below on the right is a view of the antennas taken from the west of the tower.

Below on the left you can see the 450 Mhz Cellwave Super Stationmaster antenna at the outer end of the mount. This is presently hooked up to 449.725 receiver #3 and also is used to receive the Traverse City link signal, and is also connected to the UHF control receiver. What is particularly good about this antenna, even though it's only at 100' on the tower, is that it's orientation is somewhat different giving it the ability to fill in for a bad UHF tower shadow in nearby downtown Glen Arbor. HT coverage at the local watering holes is still possible. On the left, just inside the UHF Super Stationmaster, is a dualband Diamond X50A modified for inverted mounting and connected to the 2meter and UHF packet systems. On the right side of the mount is an element from a 2mtr dipole array. This is a vestige from a former packet node and is mostly used for feeding RF through the system from my signal generator when I am tweaking things. Below on the right you can see the six meter DB products folded dipole, also at the 100' level. This antenna presently feeds the third 52.42 receiver, a 53.42 receiver, and provides some useful 'fill' when the intermittent six meter band intermod is present. Temporarily this 6mtr antenna is being used by the 2mtr remote base transceiver via a diplexer.

	To the left is the M2 Antennas 7 element 220 yagi aimed at the WB8DEL repeater in Stutsmanville. This is at approximately the 60' level on the tower.
	These photos show the tower base and the concrete block building that houses the radio equipment. The cellular phone operators have their own 'prefab' buildings to house their equipment. Below is the view from the front door showing one of the two (twin) broadcast transmitters and the combiner used to put the two 10Kw stations onto one antenna. Those large black cavities get warm to the touch!


	The wI0OK repeater rack sits quietly in the corner of the building and is watched over by the careful eye of a guard ducky-- our local control operator. This rack has removable side panels and doors and was previously used for the 147.30 repeater, many years ago. Sadly, the doors spent some time outside and need to be repainted. Regretfully, the rack is just so big and some of the gear is finding itself relegated to the top of the rack. Behind the rack are presently two (soon to be three) six meter bandpass cavities. Bolted to the rear is yet another 440 bandpass cavity for the primary 449.725 receiver. Another bandpass cavity atop the rack is for one of the other UHF receivers. Atop the rack is a stack of radios which comprise most of the packet system. Mounted above the rack, to the roof trusses, is the heliax six meter duplexer.
	This photo shows the overall view of the front upper portion of the repeater rack. There is a nice door that closes over the front of the rack which makes for a tidy looking package during normal use-- you can see a tiny part of it's hinge on the right in the photo. Thankfully, the rack has both front and back 'rack rails' so equipment can be mounted on either side of the rack. At the top of the rack is an old Motorola 'M' series Motrac base receiver (found discarded and run over by a truck at the 2002 Dayton Hamvention) which is used for the 'FCC-legal' control system. Behind this receiver is a Micor 100w power amplifier for the 52.92 repeater. Visible below the Motrac receiver is a smal Lunar GasFet preamp that's in use for one of the ancillary UHF receivers. Below the preamp on the rear rails is a Cellwave six cavity UHF duplexer. Below the tan control receiver is a black panel which supports the Motorola 'L' series Motrac receiver used to pick up the satellite voting receivers from the W8TVC location near Traverse City. This receiver has been replaced by a Kenwood TK860 that has been mounted in the same rack panel. At the middle of this view, on the rear rack rails is a Motorola Micor 100w base UHF power amplifier. Below the brown cardboard box containing 'spare parts' is the main unit of the 444.725 Motorola Mitrek used as the UHF repeater.
	In this mid rack photo, you see the Motorola Mitrek 444.725MHz and 449.725MHz main repeater transmitter and receiver sitting on a rack shelf at the top. This Mitrek has been modified for 'exciter output' as you can see the RG400 coax coming out just above the normal antenna connection. This feeds the Micor PA quite nicely and keeps the Mitrek from heating up during long QSO's. Out of view is the Advanced Receiver Research GasFET preamplifier. Below the shelf with the Mitrek is four black rack mount boxes which comprise the repeater control system. Those boxes are stuffed full of all sorts of electronics and provide a great many 'bells and whistles'. The top box holds the Arcom RC210, the second is the LDG RVS-8 voting comparator used for the 52.92 repeater. The third contains the Doug Hall Electronics voting comparator used for the 444.725 repeater, along with some ancillary controls. Finally, the fourth black box contains the seperate 'FCC Legal' control system. Under all the black boxes is a Motorola SyntorX used for the synthesized 2mtr remote base. Frequency control is via a special PIC based 'code plug' called an XCat which allows for computer control of the SyntorX. There are presently seven 'memory' channels and one 'VFO' useable with this unit. When this SyntorX is not in use for the repeater, it is connected to an MFJ1270 packet TNC and operates as the wI0OK-8 / BENQMN TheNet X1j node on 145.76.
	Below the SyntorX is a rack shelf with the weather receiver in a grey box on the left. This little weather receiver also has the ability to decode the S.A.M.E. weather alerts and feed them onto the controller to signal that threatening weather is approaching. To the right of the weather receiver is a Motorola Mitrek that comprises the 52.92MHz transmitter and 52.42MHz receiver. This Mitrek has had it's PA section removed and it feeds it's Micor 100w power amplifier directly (PA at top of rack in rear). Atop the 6mtr Mitrek is an Icom IC37A 220MHz transceiver which is the 220 link rig. This transceiver is set to 10w output power, which provides plenty of signal to access the WB8DEL Stutsmanville repeater. The IC37 sits at an odd angle for better cooling, at the expense of cosmetics. The two Astron RM70 power supplies provide the 12v for the system. The top supply powers the devices NOT on the backup battery, while the lower supply feeds a power isolator and all the items receiving emergency power. To the left of the lower Astron is an MFJ1270 TNC used for the wI0OK-8 'BENQMN' packet node on 145.76. At the very bottom, on the left is the home built power isolator. On the right is a 500 amphour deep cycle battery used to supply the repeater with emergency power.

	The complete 444.725 repeater (and 220 remote base) is equipped with emergency power and should have enough 'juice' to go for quite a few hours (more likely a few days) without problem. The six meter side will go 'dark' without commercial power. This photo shows the side of the rack with the 52.92MHz Motorola Micor 100w power amplifier at the very top on the rear (left) side. Below the six meter amp is the six cavity UHF duplexer and below that is the 444.725MHz 100w Micor power amp. There is a pair of 'muffin fans' which keep the air circulating over the UHF Mitrek and the power amps. As you can see, there are many wires connecting the various items. On the lower left is a bandpass cavity for the 145.07 packet node. Next to the bandpass cavity is yet another 52.42 receiver for the six meter repeater, this one is connected to the lower 6mtr antenna.
	Atop the rack is where most of the packet equipment has gone. Room inside the rack is at a premium, and with more improvements planned, something will need to be done to organize the 'rack top' space in order to fit more items in. I've put online a few notes on how I convert Motorola Mitrek's for repeater use, along with how I built that battery combiner. Starting at the bottom, there is a Motorola SyntorX transceiver which is the wI0OK-7 145.07 TheNet node. This has the 'hi sens' option and is tuned back to 60w. The TNC connected to this transceiver is the very top TNC, the MFJ1270 just below the Control Operator Ducky. Above the SyntorX is a UHF Motorola Mitrek which is used as the #2 449.725 repeater, and could be placed into service as a backup for the main 444.725 repeater should the other Mitrek fail. Above the Mitrek is a GE DeltaS transceiver that is currently used solely as a 53.42Mhz receiver. This will be replaced soon with another Mitrek. Atop the GE Delta is a six cavity mobile duplexer. This is used to feed RF to both the alternate 449.725 receiver and the 440.05 link receiver and provide adequate isolation from the other UHF transmitters on site. Atop the larger six cavity duplexer is yet another Motorola Mitrek. This Mitrek is the 433.125/438.125MHz bit regenerative 1200 baud packet repeater. This is the wI0OK-2 TheNet port. Atop this Mitrek is a smaller Sinclair six cavity mobile duplexer which handles the duplexing for the 433/438 system. The TNC associated with this packet node is the lower of the two MFJ1270's. I have a special packet page with information on the local packet systems and how to get the most out of TheNet and Jnos from a users perspective.
	If you stand in front of the repeater rack and look up you can see the eight stub heliax six meter duplexer. This was the first of these that I've built using the WB5WPA design. This duplexer works great and has been trouble free. Thanks to Del WB8DEL for donating the heliax (amongst other things). The duplexer fits nicely on a 4' x 2' piece of OSB and mounted to the bottom chord of the roof trusses. It was tough to get it up there, but it's out of the way.
	I plan to build another of these duplexers, with more 'beefy' interconnecting cables, and then crank the power on 52.92MHz up to the full 100w the system is capable of. I hesitate running the system at full power as I used RG58 in the interconnecting cables and wish for more 'reserve' power handling capacity. I have a page with more info on building one of these 6mtr duplexers.