A Unique Astro Question

TexasWolf · Post by **TexasWolf** » Sun Sep 17, 2006 7:56 pm

I've been lurking here for a while and now I have a question that is odd. I have a VHF with the following info:
ID#D04KKH9PW7AN-UCM
Flash Code: 580001001A409
This radio came to me through a gentleman that was trying to set up a commercial account and had several of these radios to set up his demo. He didn't win the bid and I ended up with some of the radios. This radio in particular has an attachment on the back that basically splits the RX and TX antenna hookups into two seperate plugs. My questions are:
1) What purpose would this serve?
2) Do I need seperate types of antennas for TX and RX or just two of the same?

Obviously, I'm a radio neophyte and know virtually nothing other than what I've read here. Any education you can give me would be greatly appreciated. I have a pic of the device attached to the radio but not sure how to attach it here.

Thanks in advance.

mancow · Post by **mancow** » Sun Sep 17, 2006 8:07 pm

Try imageshack.us for file hosting. You can upload the image then paste the link to it that they give you and it should display here.

TexasWolf · Post by **TexasWolf** » Sun Sep 17, 2006 8:23 pm

TexasWolf · Post by **TexasWolf** » Sun Sep 17, 2006 8:24 pm

Hope those help somewhat.

mancow · Post by **mancow** » Sun Sep 17, 2006 8:37 pm

What does it say on those cylinders on the back? That's an odd setup.

Rayjk110 · Post by **Rayjk110** » Sun Sep 17, 2006 8:38 pm

Possibly some type of Lightning arrestor/Rf PreAmp?

Just a shot out in the dark.

mancow · Post by **mancow** » Sun Sep 17, 2006 8:40 pm

Notice the sticker on the top that says Class II vessel only. What's up with that?

mancow · Post by **mancow** » Sun Sep 17, 2006 8:41 pm

I wonder if it isn't some sort of preamp setup. Maybe they split the RF paths to isolate the preamp from the TX RF.

RFguy · Post by **RFguy** » Sun Sep 17, 2006 8:50 pm

I am guessing an attenuator.

Rayjk110 · Post by **Rayjk110** » Sun Sep 17, 2006 8:54 pm

mancow wrote:I wonder if it isn't some sort of preamp setup. Maybe they split the RF paths to isolate the preamp from the TX RF.

That's kinda what I'm thinking.

- If you're out at sea (as the label would indicate to on the radio), you would probably want the most gain as possible, and isolating the TX Rf from it just makes sense. Altho they were probably designed for US Navy, I'm guessing, because I couldn't see a regular civilan class II vessle with an XTL. Mebey Doug knows.

Post by Pj » Sun Sep 17, 2006 9:07 pm

Someone here not too long ago had one of these radios. I am guessing that some agency recently dumped them. His had the seprate tx/rx, but everything else appeared to be the same.

tvsjr · Post by **tvsjr** » Sun Sep 17, 2006 9:07 pm

Those aren't XTLs, they're Astro Spectras.

I would expect they're trying to make the radios full-duplex, thus removing the T/R relay and bringing the TX/RX out as discrete runs. I'd expect the cylinder is a notch filter to keep the TXer out of the RX. This would mean the setup is frequency specific - the notch would have to be retuned to accomodate other channels.

It's not an amp... there's no power running to it (well, they could run DC biasing down the coax... I doubt it).

TexasWolf - how about some more photos? Specifically, of the black model/serial tags and whatever the round sticker is on top.

I suspect you are not going to be able to bring these up as typical VHF mobiles without some component swaps or an external duplexer. Although, if they can be turned into full-duplex VHF radios, they are interesting for other purposes.

Post by Pj » Sun Sep 17, 2006 9:10 pm

http://batboard.batlabs.com/viewtopic.php?t=59931

TexasWolf · Post by **TexasWolf** » Mon Sep 18, 2006 2:52 am

That other thread is by a gentleman who bought two of the radios I had. Little did I know he'd been posting here for the answers to the same questions. I'll go through that thread and see what was discovered.

As for the Class II use sticker, these were set-up for ocean use.

Thanks for looking, folks.

compuman81 · Post by **compuman81** » Mon Sep 18, 2006 5:13 am

This type of configuration is used when antenna space is cricital. I.E. hook two radios to the same antenna with duplexer use and all. You can configure 2 radios like that and it will allow you to transmit and receive through the same antenna on both radios. One radio can be transmitting and the other receiving, etc. That's probably a filter to keep the noise floor down when the other is keyed up.

KK5FM · Post by **KK5FM** » Mon Sep 18, 2006 6:36 am

The other gentleman who has some of these radios is JonBoyOK. I bought one of them from him, and I can add that the cylinder is not an attenuator. The radio picks up very, very well in the 155mHz range.

willbartlett · Post by **willbartlett** » Mon Sep 18, 2006 10:07 am

What is the part # on the cylinder. It's a mini-circuits part, filter probably.

Will

KK5FM · Post by **KK5FM** » Mon Sep 18, 2006 6:32 pm

Yes, it has the following on four lines:
mini-circuits
15542
Model SLP-200
10314

willbartlett · Post by **willbartlett** » Mon Sep 18, 2006 6:46 pm

200mhz low pass. +27dbm max. Who Knows. Must have been for something full duplex. I can't think of any other reason. I haven't looked at a spectra amp schematic in a while. Maybe it goes directly to the RF board. Most likely there's a low pass as part of the PA section and they needed to maintain emmission spec when bypassing it.

Probably wouldn't be too big a deal to undo it. Unless it's SP firmware, then who knows?

willbartlett · Post by **willbartlett** » Mon Sep 18, 2006 6:50 pm

Also, does the litle round sticker say "I've been FLASHED" or am I missing something. Sounds like a strong cantidate for a Hamsexy photoshop. Perhaps they can figure something out for Dayton next year. Booth babe type of stuff. Give CES a run for the money. Plenty of time to mull that over.......

tvsjr · Post by **tvsjr** » Mon Sep 18, 2006 8:27 pm

Good eye... it does say something about being flashed.

As for the rest of that comment... wtf?

willbartlett · Post by **willbartlett** » Tue Sep 19, 2006 8:00 am

As for the rest of the comment. The Hamsexy folks always come up with good stickers to hand out at Dayton. I was thinking somebody would have come up with a sticker that says something like "I've been WHOREFLASHED" or something equally fun. Like the Skyporn stickers, ya know?

Will

compuman81 · Post by **compuman81** » Tue Sep 19, 2006 8:07 am

I think that sticker is legitamate actually. I've seen quite a few of those on new radios.

Post by Pj » Tue Sep 19, 2006 9:01 pm

Another possibility that I just though of... these may have not have been produced by Motorola, but up fitted by another company. It wouldn't be the first time. Some of the Harris locotrol radios are just modified spectra's. I have pics of those somewhere.

ScannerDan · Post by **ScannerDan** » Tue Sep 19, 2006 9:16 pm

Pj wrote:Another possibility that I just though of... these may have not have been produced by Motorola, but up fitted by another company. It wouldn't be the first time. Some of the Harris locotrol radios are just modified spectra's. I have pics of those somewhere.

And remember that the old US Air Force Presidential Echo/Foxtrot Air Force One radios were modified Mitrek Mobile radios that a outside company modified.

Post by Pj » Tue Sep 19, 2006 9:38 pm

Can you find the FCC Type Acceptance label on the radio and post the FCC ID?

MattSR · Post by **MattSR** » Tue Sep 19, 2006 9:57 pm

willbartlett wrote:As for the rest of the comment. The Hamsexy folks always come up with good stickers to hand out at Dayton. I was thinking somebody would have come up with a sticker that says something like "I've been WHOREFLASHED" or something equally fun. Like the Skyporn stickers, ya know?

Will

Hahahaha I love it!

Post by Pj » Tue Sep 19, 2006 10:02 pm

ScannerDan wrote:
Pj wrote:Another possibility that I just though of... these may have not have been produced by Motorola, but up fitted by another company. It wouldn't be the first time. Some of the Harris locotrol radios are just modified spectra's. I have pics of those somewhere.
And remember that the old US Air Force Presidential Echo/Foxtrot Air Force One radios were modified Micors Mobile radios that a outside company modified.

A Unique Astro Question

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