N4KVE
Member
That's what's happening here in South Florida. They're set up to rx in mixed mode, but to xmit analog. Tha Mstr 2's will still be running long after these Fusion machines will burn out. Lots of overheating problems with them.
Yaesu System Fusion DR-1X repeater issues
- Thread starter N4KVE
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While the DR-1 can put out 50 watts the consensus is to run them at half that. That seems to have addressed this problem.
I've heard a potentially even better solution (and we're looking more into it) is to pad down the output to something like 200 mW and excite an external PA.
N4KVE
Member
They should fix the problem rather than apply a bandaid, & run it at lower power, & have to pay more $ for an amp. They were originally advertised to run at the full power setting, but after many burning out their finals, the bandaid was to run them at half power. We have Master 2's running at full power for decades on the original finals. But people jump at the offer of a $500 repeater. Don't throw out those GE's yet. LOL.
These comments were posted in a thread intended for clubs, repeater trustees, and users to post information about Yaesu System Fusion repeaters on the air. If you want to debate the operation or quality of these repeaters, that thread is not the place to do it.
I don't think Yaesu ever advertised them as 50 watt 100% duty cycle repeaters. Many so-called 50 watt repeaters of modern vintage are actually not rated for 100% duty cycle at that power, so Yaesu's design approach regarding power output is not that much different from what the rest of the industry is doing.
I don't think Yaesu ever advertised them as 50 watt 100% duty cycle repeaters. Many so-called 50 watt repeaters of modern vintage are actually not rated for 100% duty cycle at that power, so Yaesu's design approach regarding power output is not that much different from what the rest of the industry is doing.
N4KVE
Member
Right off their website.
Transmitter
RF power output 50/20/5 W
Modulation type F1D, F2D, F3E Variable Reactance Modulation
F7W 4FSK (C4FM)
Spurious emission At least 60 dB below
Transmitter
RF power output 50/20/5 W
Modulation type F1D, F2D, F3E Variable Reactance Modulation
F7W 4FSK (C4FM)
Spurious emission At least 60 dB below
Aero125
Member
A great place for info and discussion on this topic/question is the Yaesu Fusion Yahoo group. There are many DR-1X operators on there and this question has been discussed including responses directly from Yaesu. It is common knowledge and the overall conclusion the repeater is not designed for a 100% 50W duty cycle.
It is common knowledge because Yaesu representatives have said so on-line and in webinars. While their web site says 50/20/5 watts, it does not specify duty cycle.
K5MPH
Member
That's the way to go let the amp do all the work and save the PA inside the Repeater.........
N4KVE
Member
I spoke to the guy who used the 1st Fusion repeater in Florida as a beta tester. At that time, he was told they were rated at 50 watts all day long. It wasn't until after a bunch of finals blew that they dropped the rated capacity to 20 watts. The heat sinks where they mated to the radio were not finished smoothly, so they didn't make 100% contact, and wouldn't absorb the heat efficiently. They had to take all the repeaters here in the USA, remove the heat sinks, & send them to a machine shop to make a smooth cut, so they would efficiently dissapate the heat. Even after this, they still recommend 20 watts constant power. The repeater is basically 2 mobiles in a box. GARY
N5TWB
Member
This is the route we're going to go because a member volunteered a commercial amp he wasn't using. Just waiting for Yaesu to notify me they're ready to ship. On 10/1, they said they were 30-60 days behind.
k6cpo
Member
Section 97.313 (a) of the amateur radio regulations states "An amateur station must use the minimum transmitter power necessary to carry out the desired communications."
k6cpo
Member
Whatever it takes to make the contact. If you can make the contact with five watts, then you aren't supposed to use 50 watts to make the same contact.
Tell the "Full Legal Power" guys that on HF. If you don't run 1,500 Watts they can't hear you.
N4KVE
Member
The post was about the repeater dropping from 50 watts to 20 watts due to overheating. How is a repeater supposed to know how far away the user is, & drop it's power accordingly?
You don't understand how repeaters work.
Let's focus on the OP's topic rather than debating a regulation which doesn't apply here.
Thanks.
Thanks.
Project25_MASTR
Millennial Graying OBT Guy
P25 and DMR have provisions for adaptive modulation (on the subscriber side) which actually adjusts the power of the subscriber to use the minimum power necessary. Doesn't mess with the repeater though.
From what I remember from reading the manual, it does actually state 100% duty at 20W. What defines the rest of the industry? We live in a world where 95% of the amateur repeaters in service are modified commercial repeaters. The commercial industry has been selling low duty repeaters for business and full duty repeaters for public safety use for decades. It's since been understood that if you need a repeater to have more than a 25% duty you just upgrade to a PS line or turn the power down.
Yes I fully agree. Our UHF Fusion repeater has replaced a 40 year-old Mastr II so we're looking into repurposing the PA from it for the Fusion.
Right now we're running our Fusion at 20 watts and, while anecdotal, we haven't seen an appreciable difference in "talk range" compared to the Mastr II running at 40 watts.
One huge improvement we've observed is the analog receive sensitivity on the Fusion is surprisingly so much better now. We're getting handheld coverage in places we never had before. And nothing else has changed: same duplexers, same feedline and same 4-bay antenna.
Project25_MASTR
Millennial Graying OBT Guy
I don't know what the exciter on a Mastr 2 mobile puts out but I do know it puts out around 2W on a station. The only reason I know this, in a pinch Mastr 2 stations PAs can be interchanged (you have to make some modifications for long term use) with Micor PA's. Our local Saltgrass repeater is a 100W UHF Micor...it's been running on exciter power for about a year now and next to no one has noticed it (because no one uses it more than 10 miles away).
I've heard some weird things about YSF and mixed mode but that's not related to the PA.
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