The 147.10 Repeater is the North Al DX Club’s (NADXC) back-up repeater and was adopted by Ron Shaffer (KS4LU) as trustee & custodian under an agreement with the DX club in 1997. In Early 1999, The Marshal Space Flight Center’s Amateur Radio Club (MARC) worked out an agreement with the NADXC and KS4LU to pool the equipment from the 147.46 / 146.46 WA4NZD repeater with the 147.10 Machine. This arrangement along with some great team work from the folks in both organizations produced the much improved repeater system that exists today.

The repeater is located on Weeden Mountain at N 34d 31m 02s, W 86d 39m 02s. As you drive around Huntsville and look towards Redstone Arsenal you can see two mountain tops bearing towers. Madkin is the southern peak with 4 towers and Weeden is the Northern Peak with a single tower. As you travel westward on Airport Road for example, you are looking right at Weeden Mountain. The site elevation is 1176 ft above sea level and the Primary 147.10 Antenna is at the 110 ft mark on the tower giving us a height above average terrain (HAAT) of about 570 ft. From this centralized location, excellent coverage of the Huntsville area is achieved.

In it’s current configuration, the repeater consists of a Hustler G-6 Antenna mounted at 110ft, a new run of Andrews 1/2" Heliax , A set of Sinclair coaxial hybrid duplexers , a 30 amp Lab power supply, a 40 Watt G.E. Master II VHF Radio , and a CAT-500 controller. We also have the Hustler G-7 (about 1 dB more gain than the G-6) antenna which we plan to mount at the 55’ level for additional configuration options. The original NADXC RF/Controller drawer stands ready as an able back-up to the main repeater. We are still experimenting with configuration options. Currently we are borrowing the MARC Dual band antenna at 40’ for Transmit through the Duplexer. The Master II is idled down to 20 Watts output and we loose about 3 dB in the duplexer. We are currently bypassing the duplexer on the receive side, running directly to the top mounted G-6 antenna. This configuration works well for now but is subject to change.

The MARC phone line formerly serving the 147.46 Machine is now hooked to 147.10. We share the line with a NASA repeater so please be patient if you don’t get a dial tone when attempting a patch. The Phone line was necessarily configured for touch tone but the CAT-500 only supports Pulse Dialing. For this reason, we felt it prudent to set up a semi-closed patch. It is certainly open to any MARC or NADXC member or any frequent user, we just need to track who has the codes in order to be good stewards of the phone service. Just see Ron: KS4LU [email protected], or Don: N4MSN [email protected] for the details.

The current configuration for mission audio is still through the 147.70 Vox operated transmitter in the MARC shack at Building 4622. You should have little trouble talking over it to carry on a QSO however improvements are planned. KS4LU & WB4TUR (with a bit of advice from KD4FMN !) are working on a system which will couple (through an isolation transformer) into the audio feed for the 173.025 Tx at Weeden. We will use an output from the CAT to turn the mission audio to 147.10 on and off remotely. (no more running back and forth to the MARC shack every time a launch delay occurs !) It will be Vox operated so as not to keep the 147.10 Tx up and will also be ANDed with repeater COS. The mission audio will be temporarily be muted when a user keys up on the repeater input. (no more heterodyning with mission audio from repeater shaded areas!) We will keep you posted on our progress.

We plan to mount the Hustler G-7 antenna at the 55’ mark where the old NADXC Ringo is perched. This will give us the flexibility to run split antennas if needed and free up the MARC Dual Band antenna for the UHF machine if it returns to service. There is also some options available to replace the CAT-500 with a DTMF encoder capable controller which would clear up the autopatch access inconvenience and add other capability as well. Other improvements could include a receiver pre-amp and other duplexer / cavity filter options.