52.68 K8SGX Repeater?

[ad8g]

Just got word from Bill, he disabled the repeater because something weird is causing the UHF receiver to key up. Later today I'll probably just disable UHF and then re-enable 6.

So if you throw out your call and it doesn't come back...... that's why

 

[wd8chl]

Someone made a comment about the transmit antenna. Last I heard, because of the power levels involved, a custom antenna array was constructed using 3 or 4 A/S folded dipoles, similar to the DB-212, and a custom power divider. Getting an antenna that can handle 1500 watts is not easy.
I used to be involved back in the late 90's and 2000's, but my work situation changed and I was not able to keep a 6M radio in my vehicle, so I had to drift off.
I hope to change that next year, if I can find the Orion I had started to put together about 5 yrs ago...

 

[KC3ECJ]

Low band does not support P25

I thought the military had P25 capable low band radios.

 

[ad8g]

Someone made a comment about the transmit antenna. Last I heard, because of the power levels involved, a custom antenna array was constructed using 3 or 4 A/S folded dipoles, similar to the DB-212, and a custom power divider. Getting an antenna that can handle 1500 watts is not easy.
I used to be involved back in the late 90's and 2000's, but my work situation changed and I was not able to keep a 6M radio in my vehicle, so I had to drift off.
I hope to change that next year, if I can find the Orion I had started to put together about 5 yrs ago...

You're thinking of 147.015.

F2 is on a standard antenna with custom-made brackets because of the diameter of the tower leg it's mounted to..

So for 147.015 (I happen to be a director and the treasurer for it)..... it's up around the same height on the tower. The antenna system consists of 4 fiberglass antennas from Antenna Specialists, two pairs, one on each of two sides of the tower - phased with said power divider. The transmitter only puts out about 45 watts, but due to the height and antenna gain it covers several counties up here quite nicely (as I'm sure you've noticed ).

I did put up a website for 147.015, it's at https://w8oke.org

And again the page I have on F2 is at https://ad8g.net/f2/

- dave

 

[RFI-EMI-GUY]

Which one? The one in the OP is 52.68 out 52.92 in.
I don't know if it has a tone now. It didn't in the past.

What an odd offset. It is a shame the 6M repeater band has so many weird offsets. I have a 128 channel Syntor X9000 and it was a struggle to get all of the possible iterations programmed.

 

[tweiss3]

What an odd offset. It is a shame the 6M repeater band has so many weird offsets. I have a 128 channel Syntor X9000 and it was a struggle to get all of the possible iterations programmed.

Agreed. It didn't line up with the step of my VX7R, so I was forced to add it with the program cable.

 

[RFI-EMI-GUY]

I thought the military had P25 capable low band radios.

They do have multi waveform radios which can support P25 in low band. There have in fact, been reception reports logged of low band P25. There really is no reason other than for encryption to do P25 in low band because (for Part 90 users) FCC still permits wide band channels. Securenet CVSD and DES was widely used in past.

AN/PRC-148 MBITR/JEM

Multiband Inter/Intra Team Radios.

www.thalesgroup.com

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PRC-154 with 75th RR (click to view full) The Pentagon's JTRS (Joint Tactical Radio System) aimed to replace existing radios in the American military with a single set of software-define radios that could have new frequencies and modes ("waveforms") added via upload, instead of requiring...

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[ad8g]

What an odd offset. It is a shame the 6M repeater band has so many weird offsets. I have a 128 channel Syntor X9000 and it was a struggle to get all of the possible iterations programmed.

Agreed. It didn't line up with the step of my VX7R, so I was forced to add it with the program cable.

Yeah. It's that way for historical reasons. Remember, this repeater has been around for a very long time.

 

[wa8pyr]

What an odd offset. It is a shame the 6M repeater band has so many weird offsets. I have a 128 channel Syntor X9000 and it was a struggle to get all of the possible iterations programmed.

If I recall correctly, the six-meter band didn't really have standardized offsets until relatively recently compared with those in the UHF and VHF bands. Most groups selected offsets which would work with the equipment on hand, which was converted commercial stuff with relatively narrow filters. The six-meter repeater (long gone) which was paired with the 147.240 repeater in Columbus had a similar oddball offset (I think one of the frequencies was 52.84).

 

[KA0XR]

You're thinking of 147.015.

F2 is on a standard antenna with custom-made brackets because of the diameter of the tower leg it's mounted to..

So for 147.015 (I happen to be a director and the treasurer for it)..... it's up around the same height on the tower. The antenna system consists of 4 fiberglass antennas from Antenna Specialists, two pairs, one on each of two sides of the tower - phased with said power divider. The transmitter only puts out about 45 watts, but due to the height and antenna gain it covers several counties up here quite nicely (as I'm sure you've noticed ).

I did put up a website for 147.015, it's at https://w8oke.org

And again the page I have on F2 is at https://ad8g.net/f2/

- dave

With the >700 foot height of the antenna for both the 2m and 6m machines do you get any Ontario hams across Lake Erie able to access (or use) either machine? Base stations as far away as Toronto or would that be too much of a stretch, despite the open water path?

 

[W8UU]

If I recall correctly, the six-meter band didn't really have standardized offsets until relatively recently compared with those in the UHF and VHF bands. Most groups selected offsets which would work with the equipment on hand, which was converted commercial stuff with relatively narrow filters. The six-meter repeater (long gone) which was paired with the 147.240 repeater in Columbus had a similar oddball offset (I think one of the frequencies was 52.84).

That's what I remember, too. The early commercial low band equipment had a narrow range for transmit frequencies. The original goal was to keep the repeater pair close enough to allow for simplex talk around. The 52.68 and 52.92 pair mentioned previously fits the bill and would also allow 52.525 tx/rx if you had enough crystal slots in the radio. 10 meters did the same with 29.52/29.62, etc. and 29.60 as the simplex call channel. You just need hefty (and expensive) duplexers on the system or use split sites for transmit and receive. Mobile antennas on low band VHF frequencies could be kind of wonky with wider frequency splits and I'm sure that was a secondary consideration. As the technical side of commercial radio equipment improved, the 1 MHz split on 6 meters was doable. My guess is there are way too many legacy 2 meter repeaters on the air to consider re-farming the tx/rx split away from the current +/- 600 kHz arrangement.

 

[wd8chl]

You're thinking of 147.015.

F2 is on a standard antenna with custom-made brackets because of the diameter of the tower leg it's mounted to..

So for 147.015 (I happen to be a director and the treasurer for it)..... it's up around the same height on the tower. The antenna system consists of 4 fiberglass antennas from Antenna Specialists, two pairs, one on each of two sides of the tower - phased with said power divider. The transmitter only puts out about 45 watts, but due to the height and antenna gain it covers several counties up here quite nicely (as I'm sure you've noticed ).

I did put up a website for 147.015, it's at https://w8oke.org

And again the page I have on F2 is at https://ad8g.net/f2/

- dave

Well, what I said was what Bill had said at one point about 10-15 years ago. They were specially built by A/S after the original antennas died. They couldn't get one antenna that could handle the power without spending massive $$$$$ for a broadcast grade antenna, so they used 3 folded dipoles that could handle 500 W or so each, used a power divider, and mounted them on each leg to get as omni as possible. Now, maybe all of that has been changed out in the last few years, I don't know.

 

[ad8g]

With the >700 foot height of the antenna for both the 2m and 6m machines do you get any Ontario hams across Lake Erie able to access (or use) either machine? Base stations as far away as Toronto or would that be too much of a stretch, despite the open water path?

We do from time to time, especially when the band is open. I once heard someone from Buffalo NY on the 2 meter machine... he was running 5 watts with a J-Pole on his apartment balcony!

 

[ad8g]

The 52.68 and 52.92 pair mentioned previously fits the bill and would also allow 52.525 tx/rx if you had enough crystal slots in the radio.

It's funny you mention that. When we test the remote inputs, one of the things we do is attach a 100W radio to the main transmit antenna - this is able to bring most of them up full-quieting (a couple are just too far away).

That 100W "suitcase radio" also has 52.525 in it... so when we're done, before we hook everything back up.... we'll call out on .525 and make some contacts

 

[ad8g]

Well, what I said was what Bill had said at one point about 10-15 years ago. They were specially built by A/S after the original antennas died. They couldn't get one antenna that could handle the power without spending massive $$$$$ for a broadcast grade antenna, so they used 3 folded dipoles that could handle 500 W or so each, used a power divider, and mounted them on each leg to get as omni as possible. Now, maybe all of that has been changed out in the last few years, I don't know.

Gotcha. People often confuse F2 and .015 since they're on the same site.

I don't know when last the antenna system was last modified up there, I know it hasn't been since I've been involved (since 2013 or so). The current configuration is two loops, made by Andrew, and yeah the antennas are rated at 500W. The loops themselves could probably handle a lot more, but the feedline/harness and connectors would be the limiting factor there.

Also.... Remember, while the amplifier puts out ~1200 watts, 700+ feet of feedline results in some loss, about 3dB, so by the time it gets up the tower, it's pretty close to the manufacturer's rating.

Hope that helps!



Also, I was just there today - we replaced some dirty pots in a couple of line driver cards with milspec ones. I took more photos, I'll reply here when I put them up.

 

[ad8g]

A couple of other random things while they're in my head:

We've had a couple issues with 12V circuit breakers popping. They're getting old so we're going to replace them. Unfortunately these can't be reset remotely, so it requires a ride out to the site. I have new ones on order, until then I'm doing my best to reset as needed

Also, if you're in range of the repeater and you're involved in Skywarn, don't forget to check into the backbone net every Wednesday at 8:00PM. It's just a quick checkin, no ragchew or anything like that. Takes between 5 and 10 minutes. See Wednesday Practice Net – Cleveland Skywarn for more info on that.

 

[wd8chl]

Gotcha. People often confuse F2 and .015 since they're on the same site.

I don't know when last the antenna system was last modified up there, I know it hasn't been since I've been involved (since 2013 or so). The current configuration is two loops, made by Andrew, and yeah the antennas are rated at 500W. The loops themselves could probably handle a lot more, but the feedline/harness and connectors would be the limiting factor there.

Also.... Remember, while the amplifier puts out ~1200 watts, 700+ feet of feedline results in some loss, about 3dB, so by the time it gets up the tower, it's pretty close to the manufacturer's rating.

Hope that helps!



Also, I was just there today - we replaced some dirty pots in a couple of line driver cards with milspec ones. I took more photos, I'll reply here when I put them up.

Yeah, the antennas I was talking about probably went up in the late 80's or early 90's. I was pretty active on F2 in the late 90's and early 2000's, but had to drift away with changes that came up in 2010, and haven't been able to get back to it. I have a SyntorX and an Orion, but haven't had a vehicle I could put them in until just about now...