Possibly Quintron PA? Need help identifying transistors
I have this PA and it is labeled “100W PA”.
However I cannot find the datasheet for the transistors. Motorola SRF2604.
any ideas what the range for this is?
drive needed?
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Re: Amphenol Old Style RG-393?
Looked it up in a Nemal Electronics Catalog, and you remembered correctly, Jeff. Both cables are identical except for the jacket on RG393 is -70 to +200 degree C fluorinated ethylene propylene (FEP) and OD 390 mils. RG225 is -70 to +250 degrees C and fiberglass/ silicone braid and OD 430 mils Both should say Mil C-17D, just a little higher operating temp on RG225.
John
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On 04/07/2025 6:04 PM EDT Jeff DePolo WN3A via groups.io <jd0@...> wrote:
? It is an older variant of RG-393. I know it's 393 and I know it's 50 ohms.
Apparently, I didn’t receive the original post, only your follow-up response. Questions:
1. What is the measured OD of the cable?
2. Does it have a single layer of woven braid for the jacket or two layers?
3. Does it feel like fiberglass or something else like a high-temp polymer?
4. It is actually marked Amphenol and RG-393? Any other markings, part number, etc.?
I’ve seen/used this type of cable in high-temperature and high-power applications; I even have a few jumpers here. What confuses me is that I remember it being larger in diameter than RG-393 (390 mils), and likewise, what I have here at the shop is also larger OD - 430 mils or thereabouts, close to RG-214 if not a hair bigger. What I have here has no markings on it all, but I've always known this type of cable to be RG-225.
Also, I don’t remember ever seeing any marked as RG-393, so that’s why I asked about what is printed on your cable. I do have some old Amphenol catalogs around somewhere, but in the meantime, look up RG-225 to see if that’s close to what you have.
--- Jeff WN3A
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Hi Greg,
?
Several things from the school of hard knocks...? Recheck the length of your VB-35 matching section with at least several feet of 50 ohm coax between it and your measuring instrument as I found it was different if directly connected to a tower mounted diplexer N female input, than if a length of 50 ohm coax in the middle. I do not have a DB cutting chart, but have a few more DB lengths. DB said for 53.23 MHz, the length of VB35 should be 36 5/8 inches. I have a note that for 52.8 MHz the distance from open end of the N female to the UHF barrel tightening ring should be 37" so that includes the UHF barrel. So you must be close and as you said tuning is broad.
?
If you are using the end supports to the tower leg placed out 2/3 on the element ,for 53.1 MHz 1.02SWR, top to metal center support top is 49 3/8", bottom tip to metal center support bottom is 50 3/8" (our test set-up on a tower leg free and clear)
?
We found the factory? N connectors pulled apart with tower icing and high winds, so I went to 2 piece N connectors, but if you used thick wall heat shrink like used for underground? electrical wiring, on your T and N connector, you should be OK.
?
John
On 04/07/2025 5:55 PM EDT wgwl via groups.io <wgwl@...> wrote:
?
?
Roger,
In hopes of answering your original question, I got my hands on a DB212-2 originally on 37.7MHz and shortened the antennas and matching section for 6?
meters. The 35 ohm matching section (Decibel Products VB-83 cable) was shortened?
to 36.25" end to end. With a UHF T on the end?
and two 50 ohm loads attached resulted in the attached plot. As you can see, the?
exact length is not critical across the band.
?
John,
You mentioned "DB factory lengths" in an earlier post. Do you have access to the?
actual factory length chart for 6M ? If so, please share.
?
Mike,
How well did the tuning of your antenna on the ground translate to mounting on a tower? What length of pipe did you use when tuning?
Greg
WB9TRO
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Re: MTR2000 channel steering
Such as? The RSS is pretty easy to navigate?
Chris WB5ITT?
Thanks for your input, however I'm looking for help programming the MTR2000 instead of a functional description.
73
-de John NI0K
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Re: Suggestions for service monitor
I second this. I had the same question about a month ago and ended up getting an HP8921A. It’s a good analyzer to learn on and does probably way more than you need.?
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On Apr 7, 2025, at 6:42?PM, Mike via groups.io <prcradio@...> wrote:
? For non digital stuff the HP/Agilent 8920 series.?
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Re: Suggestions for service monitor
For non digital stuff the HP/Agilent 8920 series.?
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Re: Suggestions for service monitor
The NanoVNA-V2 seems to handle doing the pass part pretty well. You're measuring return loss there, and it seems to handle that just fine. Only question I might se is if the frequency standard is really accurate enough to set it correctly-but I bet it's pretty close...
Notches on the other hand-forget it. Definitely not even close to enough range for that. Even most service monitors can't do it, or are right on the edge of doing tolerably.
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On 4/6/2025 5:34 PM, Bob Dengler via groups.io wrote: At 4/6/2025 01:35 PM, you wrote:
Ooh this is interesting. I have a NanoVNA and I think I asked here and also saw some other threads here that were saying its dynamic range is not enough to tune a duplexer. LibreVNA looks a lot more capable! I've seen reports of drift issues with the LibraVNA.? For the moment I'm happy with my VNWA 3EC (though the design is getting dated so not sure I'd recommend for a new purchase), but if I needed one today I'd try this one: < <>>
Bob NO6B
_._,_._,_
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Re: Amphenol Old Style RG-393?
? It is an older variant of RG-393. I know it's 393 and I know it's 50 ohms.
Apparently, I didn’t receive the original post, only your follow-up response. Questions:
1. What is the measured OD of the cable?
2. Does it have a single layer of woven braid for the jacket or two layers?
3. Does it feel like fiberglass or something else like a high-temp polymer?
4. It is actually marked Amphenol and RG-393? Any other markings, part number, etc.?
I’ve seen/used this type of cable in high-temperature and high-power applications; I even have a few jumpers here. What confuses me is that I remember it being larger in diameter than RG-393 (390 mils), and likewise, what I have here at the shop is also larger OD - 430 mils or thereabouts, close to RG-214 if not a hair bigger. What I have here has no markings on it all, but I've always known this type of cable to be RG-225.
Also, I don’t remember ever seeing any marked as RG-393, so that’s why I asked about what is printed on your cable. I do have some old Amphenol catalogs around somewhere, but in the meantime, look up RG-225 to see if that’s close to what you have.
--- Jeff WN3A
|
Roger,
In hopes of answering your original question, I got my hands on a DB212-2 originally on 37.7MHz and shortened the antennas and matching section for 6?
meters. The 35 ohm matching section (Decibel Products VB-83 cable) was shortened?
to 36.25" end to end. With a UHF T on the end?
and two 50 ohm loads attached resulted in the attached plot. As you can see, the?
exact length is not critical across the band.
?
John,
You mentioned "DB factory lengths" in an earlier post. Do you have access to the?
actual factory length chart for 6M ? If so, please share.
?
Mike,
How well did the tuning of your antenna on the ground translate to mounting on a tower? What length of pipe did you use when tuning?
Greg
WB9TRO
|
Re: Amphenol Old Style RG-393?
I don't think you understood my question...I am asking about this specific cable. It is an older variant of RG-393. I know it's 393 and I know it's 50 ohms. I'm aware of every RF connector. I'm looking for information on this specific style of 393. The internet is of no help on this cable. Termination is definitely different than the solid FEP because of the braided sheath. Obviously need to keep it from unraveling itself.?
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Varden duplexer model# 8D1146B
Hello all, would anyone have any tuning information on the Varden duplexer 146-148mhz. I know its a long shot, but no searches on the web produced any results.?
?
These were made by
Varden Electronics
Box 791, Jackson, Michigan
49204
?
Thanks for any information
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Re: Amphenol Old Style RG-393?
Internet has all your info, its 50 ohm and would be great for jumpers between a repeater and other stuff. Connectors are available in many types.?
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Re: 220Mhz ACSB amplifier
AH6LE,
?
Ken,
?
I wonder if? some of the same UPS AT 220 MHz amps may show up at the next Rickreall hamfest, I missed the one at Rickreall this Feb.? but maybe the one in the fall could have some available?
?
I don't remember the call of the guy who sold them to me either so it's probably a stretch hoping for some of them to show up at the Swaptober hamfest near Salem but it's worth the try.
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Re: 220Mhz ACSB amplifier
Mine didn't have any fans and no? cases on any of these amps either but they were complete and the box was marked as working 220 MHZ ACSSB amplifiers.
?
The amps all included the T/R switch, a low pass filter and bias circuitry and the same 3 transistor Motorola RF lineup.
?
An entire box of several amps was purchased back in 2013 at the RickReall Oregon hamfest from an unknown seller for only 50 dollars along with a? working ~180 watt TPL 220MHz amp.
?
The UPS/AT 220 amps were all ~ 50 watts output and most had no markings but 2 were marked? UPS AT, Salem Oregon but all of them have the same RF board design with Motorola TMOS devices in them.
?
I have used 2 of these amps with a 220 home brew Wilkinson combiner in my 220 MHz to 10 FM FM remote base system for the past 12 years without a failure, the others are spares just in case I have failure.
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Amphenol Old Style RG-393?
Hi all,?
I recently just picked up an item from Facebook marketplace, taking the chance on it. It was a roll of unknown coax. The seller took pictures of the roll and the end of the cable. I counted the center conductor stranding, and counted 7. It was silver plated. Having made tons of cable with RG-393, this was my best guess. I reached out and he shipped it to me for $50.
?
Low and behold, I have 230ft of this RG-393. However, it has a braided outer jacket, has a thin layer of what I think is PTFE? separating the outer braided jacket from the shield. There are two silver plated copper shields, then wrapped PTFE? around the center conductor. Does anyone have any info on this cable? Data sheets? Tricks for terminating it? From what I can find out, it was used for military applications. I have attached a few photos of it.
?
Thanks,
Joe KC3LMP
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Re: ICOM/RLC/CommSpec Items or Sale
Hi Scott!? ?All the 901 stuff has been sold.? ?Thanks for asking.
?
Craig AA6CG
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Re: Kenwood NXR 810 repeater
I'm not reassigning the RS232 pins 2&3. Channel select uses AUXIO1 to AUXIO4, pins 20 to 23.
Joe
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On 4/6/2025 8:37 PM, Ken Arck AH6LE via groups.io wrote: Not really. The RS232 pins can't be reassigned.
Ken
At 05:23 PM 4/6/2025, you wrote:
Very good point.? I use pins on the db-25 of one of my TRK repeaters for channel steering.? With the db-25 off and no steering pins grounded the repeater will fault and not key up.
Joe, K1ike
On 4/6/2025 5:33 PM, n5qs via groups.io wrote:
Another caution
Be sure the DB25 on the back has not had some of the rs232 pins reprogrammed to another function.
If I am programming a repeater that has been programed by someone else I never use anything except the 8 pin on the front until I have checked the pinout on the DB25,
many people dont know to leave certain pins at the default.
Roger
On 4/6/2025 8:19 AM, Joe wrote:
I prefer to use the 8 pin modular cable.?? That allows me to go to a site and make programming changes from the front panel of the repeater and not have to go in the back and possibly remove a db-25 that connects to something else like a controller.?? The less time I spend in the back of the rack, the less time I have to accidentally disconnect something else.
Joe, K1ike
On 4/4/2025 7:09 PM, Ken Arck AH6LE via groups.io wrote:
That would work too but the only time that connection is absolutely necessary is when uploading firmware to the repeater (same as the TKRs). Otherwise, the DB25 on the back panel is fine (straight through, non null modem connection)
Ken
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Makers of repeater controllers and accessories
Phone: (503) 678 6182
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Re: MTR2000 channel steering
Best of luck.?
tnx Mike / K5JR? Alpharetta GA
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On Apr 7, 2025, at 8:50?AM, john ni0k via groups.io <jasimmons@...> wrote: ?
Thanks for your input, however I'm looking for help programming the MTR2000 instead of a functional description.
73
-de John NI0K
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Re: MTR2000 channel steering
Thanks for your input, however I'm looking for help programming the MTR2000 instead of a functional description.
73
-de John NI0K
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Re: Where did db Products go?
In related news Andrew was acquired by Amphenol and is coming back to the Andrew name.?
By the way the proper spelling should be and db Spectra "claims" they carry them, which was my source of confusion. I'll stay with Comscope.
--
-
Regards, Karl Shoemaker
To contact me, please visit SRG's web site at?
for the current email address.
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Chris Boone WB5ITT
Tom VA3TS
Craig