Anzac H-125 hybrid junction  - Page 1
Forum section: electronics / rf-microwave

author: bsalai
author_rank: Regular Contributor
timestamp: February 17, 2017, 07:11:02 pm
content: I found this in my junk boxwhile I was looking for something else. I can't remember when or where I got it, but it was likely 30 or 40 years ago. I can't find any information about it on the web, does anyone recall it or have any information about it?Sent from my iPhone using Tapatalk

author: tombi
author_rank: Regular Contributor
timestamp: February 20, 2017, 01:08:40 am
content: Hmm - Found some other Hybrid power dividers with other H numbers but not h-125.Like this one.https://www.radio741.com/categories/power-divider-combiner/bnc-hybrid-junction-anzac-h-5-detail.htmlTom

author: AF6LJ
author_rank: Unknown
timestamp: February 20, 2017, 04:31:02 am
content: Quote from: bsalai on February 17, 2017, 07:11:02 pmKnow anybody with network analyzer...A scailer network. analyzer would do.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: February 20, 2017, 05:04:32 am
content: Quote from: AF6LJ on February 20, 2017, 04:31:02 amNot quite - if it's a hybrid, the phase shift between the output ports can be 90 degree or 180 degree. Of course, one might not care what the phase shift is...

author: bsalai
author_rank: Regular Contributor
timestamp: February 20, 2017, 01:04:00 pm
content: I'll see if I can find somebody, but in the meantime what do you think about the idea of feeding a signal from a signal generator into one port and looking at the other two ports on the scope. That should give me an idea of the magnitude and phase don't you think?Sent from my iPhone using Tapatalk

author: AF6LJ
author_rank: Unknown
timestamp: February 20, 2017, 01:55:17 pm
content: Quote from: bsalai on February 20, 2017, 01:04:00 pmI think that is a good idea

author: AF6LJ
author_rank: Unknown
timestamp: February 20, 2017, 01:59:02 pm
content: Quote from: radar_macgyver on February 20, 2017, 05:04:32 amGood Point however...This will get him into the ballpark...Frequency wise...I would open it up to see what type of combiner it is.That would be the best way to gain some insight into what it actually is and what to expect from it.

author: bsalai
author_rank: Regular Contributor
timestamp: February 20, 2017, 08:15:45 pm
content: As long as I'm careful, is there any risk in opening it up? It isn't hermetically sealed is it??Sent from my iPhone using Tapatalk

author: AF6LJ
author_rank: Unknown
timestamp: February 21, 2017, 02:42:14 am
content: Quote from: bsalai on February 20, 2017, 08:15:45 pmJust be real careful and don't touch anything.If you can take a pictureI am assuming those are N connectors on the package.It doesn't look like it is back filled with nitrogen If it was there would be a seal screw with a gasket.

author: bsalai
author_rank: Regular Contributor
timestamp: February 21, 2017, 03:13:47 am
content: They are N connectors. I didn't see any sign of a seal screw, I'll look again and if I don't find one, I'll try taking it apart carefully. I'll definitely post a picture of what I find.Sent from my iPhone using Tapatalk

author: bsalai
author_rank: Regular Contributor
timestamp: February 21, 2017, 07:10:11 pm
content: Here are some pictures:The conductors look relatively large to me, 16–18 gauge?Five of the Bobbons have a single winding, the sixth one, the one with the small external coil next to it appears to have two windings. Each of the end connectors has a small phenolic for that has the center pin on one side and a connection on the other side, possibly a capacitor? I'll make some measurements.Sent from my iPhone using Tapatalk

author: AF6LJ
author_rank: Unknown
timestamp: February 21, 2017, 07:31:24 pm
content: Given the lead liengths and the point to point wiring as apposed to a circuit boar, it looks like this was intended to be used in the 3-60MHZ range or maybe the low TV channels.

author: bsalai
author_rank: Regular Contributor
timestamp: February 21, 2017, 08:45:25 pm
content: Does the fact that the paths are not identical suggest that there is an intention to introduce a phase shift?Sent from my iPhone using Tapatalk

author: bsalai
author_rank: Regular Contributor
timestamp: February 21, 2017, 08:50:35 pm
content: Also, there is continuity between all three center pins of the N connectorsSent from my iPhone using Tapatalk

author: bsalai
author_rank: Regular Contributor
timestamp: February 21, 2017, 08:53:49 pm
content: I'll hook it up to a scope and see what the phases look like. I wonder what the small pieces of what looks like circuit board at the three connectors is for.Sent from my iPhone using Tapatalk

author: AF6LJ
author_rank: Unknown
timestamp: February 21, 2017, 11:31:22 pm
content: I would agree.

author: bsalai
author_rank: Regular Contributor
timestamp: February 23, 2017, 12:02:46 pm
content: I looked at the phase difference between the two outputs and it is small between 3 and 50 MHz. This seems odd to me because of the different configurations of the first inductors in the signal paths. But my knowledge of such things is very limited.Given that it seems to work in the HF range, and produces in phase outputs, what would it be used for. I suppose it could split a signal between two antennas. Would that be likely to be a principal use?Sent from my iPhone using Tapatalk

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 23, 2017, 02:21:20 pm
content: Is that all solid wire, orhardline?Wouldn't think it would be all that useful if the ports go right into inductors. But, if that's the case, and the wire is solid, then, I would suppose it was for fairly low frequencies (bottom of SW, if not MW or LW), and modest power levels (under a kW?).Tim

author: bsalai
author_rank: Regular Contributor
timestamp: February 23, 2017, 02:29:42 pm
content: It looks like solid, insulated wire, not dressed particularly carefully, so I'd say it's for relatively low frequencies. It is pretty robust looking, so probably for moderate power, but less than a kw as you suggested. The inductors don't look like they are for LW.Sent from my iPhone using Tapatalk

author: capt bullshot
author_rank: Super Contributor
timestamp: February 23, 2017, 02:44:48 pm
content: My guess:A hybrid would be a circuit to split a Rx path and a Tx path in the same frequency range.Widest usage was in POTS, there's been a small transformer to split the audio band (talking and listening over a single twisted pair of wires) to microphone and earpiece, to attenuate your own voice (so you don't hear yourself talking).I could imagine this thing is doing something alike for higher frequencies, especially if there's one of the cores with two windings. The other ones might be for some kind of impedance matching which is particular important for a high Tx/Rx separation hybrid.

author: AF6LJ
author_rank: Unknown
timestamp: February 23, 2017, 11:49:04 pm
content: Quote from: bsalai on February 23, 2017, 02:29:42 pmIn most HF applications the ports would be in phase.I am assuming all ports were terminated...And it does make more sense if the "wire" was actually something like .070" hardline.

author: bsalai
author_rank: Regular Contributor
timestamp: February 24, 2017, 12:59:59 am
content: Would the hardline explain the small plates at each connector? Possibly the outer conductor is connected to one side and the center conductor passes through and connects to the connector center pin?Sent from my iPhone using Tapatalk

author: rfeecs
author_rank: Frequent Contributor
timestamp: February 24, 2017, 01:53:40 am
content: I usually call it semi rigid cable.I was thinking the same thing. Possibly the boards at the connectors are to give a good ground at the center pin. That is, with a ground plane on the back side. The semi rigid outer conductor may be soldered nicely all around to ground on the back side, and the center conductor coming up through a hole to the front, maintaining a nice 50 ohms.It would be interesting to see what is going on with the other boards and why the complicated little board with the two perpendicular pieces.If its a hybrid, zero degrees or 180 degrees or 90 degrees, the bandwidth defining spec would probably be isolation between the two ports. Terminate the common port, then put a signal in one port and see what comes out the other. I'm wondering if the frequency band is actually higher than you have looked.

author: AF6LJ
author_rank: Unknown
timestamp: February 24, 2017, 02:05:39 am
content: Quote from: rfeecs on February 24, 2017, 01:53:40 amGood Call.

author: bsalai
author_rank: Regular Contributor
timestamp: February 24, 2017, 02:18:39 am
content: I'll have to make a terminator, but shouldn't be too hard. I'll be back with more data.Sent from my iPhone using Tapatalk

author: AF6LJ
author_rank: Unknown
timestamp: February 24, 2017, 12:57:04 pm
content: That should work, however all three ports need to be terminated with something.

author: bsalai
author_rank: Regular Contributor
timestamp: February 26, 2017, 12:44:22 am
content: Here's what I did. I terminated the common port with 50 ohms. I fed a signal into one of the other ports and connected it to a 50 ohm input of my scope. I measured the output of the signal generator with the same scope, but only connected to the scope.The signal generator output was 300mV, the output of the port that the signal generator wasn't connected to was 5mV. I tried calculating the power ratio, using P=E squared/50 and got 90 db. That seems unlikely, where did I go wrong?Sent from my iPhone using Tapatalk

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 26, 2017, 01:22:36 am
content: log10(300 / 5) * 20 = 35.6 dB.The 20 getsdecibels from volts. If you use power, it's 10. Multiplication outside a log is exponentiation within the log, and power goes as volts squared, so this is equivalent.Tim

author: bsalai
author_rank: Regular Contributor
timestamp: February 26, 2017, 01:29:27 am
content: Got it, thanks. That is a reasonable number I would think.I tried a range of frequencies, the isolation starts to drop above 50MHz. It stays pretty constant down to 700kHz.Sent from my iPhone using Tapatalk

author: bsalai
author_rank: Regular Contributor
timestamp: February 26, 2017, 02:05:55 am
content: I'm wondering what I could use it for. The isolation isn't quite enough to connect a transmitter and receiver to one antenna. Maybe a QRP transmitter?Sent from my iPhone using Tapatalk

author: AF6LJ
author_rank: Unknown
timestamp: February 26, 2017, 02:08:05 am
content: That is interesting, a lot of loss.Would be interesting to feed the generator into the common port.Connect the scope to one port and terminate the other.

author: bsalai
author_rank: Regular Contributor
timestamp: February 26, 2017, 02:09:35 am
content: I'll try that in the morning. I could try it tonight but then I would be single in the morning!Sent from my iPhone using Tapatalk

author: bsalai
author_rank: Regular Contributor
timestamp: February 26, 2017, 02:17:13 am
content: I tried it. 120mV out. Both ports are the same.Sent from my iPhone using Tapatalk

author: edpalmer42
author_rank: Super Contributor
timestamp: February 26, 2017, 03:28:36 am
content: Quote from: bsalai on February 26, 2017, 02:05:55 amI've been following this thread with some interest. I've never used a hybrid junction and wanted to see what the result was. When I looked around, I found this one:http://www.ebay.com/itm/321364367967. I'm still not sure what you'd use it for, but if yours works the same, a dual trace scope hooked up to the two outputs should show the phase shift.Ed

author: bsalai
author_rank: Regular Contributor
timestamp: February 26, 2017, 09:05:07 am
content: I have done that, but without terminating the ports and the phase difference was no more than a few degrees between the output ports. I'm going to try it again with terminators on the ports ahead of the high impedance scope inputs.Sent from my iPhone using Tapatalk

author: bsalai
author_rank: Regular Contributor
timestamp: March 20, 2017, 10:35:11 pm
content: I finally got the terminators that I need put together and have made some measurements that just might be valid. Connecting the signal generator to what I will call the input port, terminating one of the outputs and measuring the signal at the other using a 50 ohm termination at the scope input gives approximately a three dB loss from just below 1 MHz to about 60 MHz. The phase changes from about 0° at the low-end to about 180° at 60 MHz.The isolation between the output ports is about 40 dB from below 1 to 60 MHz and decreases above that.Now the question is, what can I make with it.Brad W2EKSent from my iPhone using Tapatalk

author: AF6LJ
author_rank: Unknown
timestamp: March 20, 2017, 11:05:08 pm
content: Very cool, I wonder what the phase change is at say 20, 30, and 45 MHZ...

author: edpalmer42
author_rank: Super Contributor
timestamp: March 20, 2017, 11:20:54 pm
content: Does the phase shift continuously with frequency or is there a frequency range where the phase shift is constant, maybe at 90 degrees? If so, I suspect that range would specify the operating range of the unit.As for what you can do with it, wellEd

author: bsalai
author_rank: Regular Contributor
timestamp: March 21, 2017, 02:14:50 am
content: I will get some proper data but I think the phase shift was continuous with frequency. I'm away for a week but will do this when I get back.Sent from my iPhone using Tapatalk

author: AF6LJ
author_rank: Unknown
timestamp: March 21, 2017, 03:40:41 am
content: Quote from: bsalai on March 21, 2017, 02:14:50 amSounds good and I would expect it to be a fairly constant change.