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I thought it didn't work,but for 3 After all, someone turned it on a few days ago. Before that, it responded to the 1750Hz tone even when I whistled it with my mouth, but now it has no chance, even though I have to say that I also whistle other frequencies perfectly (hi)
Hi Ervin.
So, after all – there is some problem, at least it was confirmed. True, smugglers age like us :), we probably need to gradually think about their restoration – specifically also OVR. He already has something used. In case of interest from VO (I do not know, who is), I can provide a 6-cavity duplexer (approx 130-140 €) and Zetron would probably be too (model 30) for controlling Motorola mobile phones of the GM type, M. It shouldn't be a problem to find stations either. If there is interest in it, go for it, let the competent person get in touch with me.I don't know, how did you come up with the amount 130-140 EUR for a 6-cavity duplexer for 145 MHz, it's more like the price for 430 MHz. Unless you have a duplexer in an air-conditioned room, and if I remember, so there is no such room on the King's Scepter, so you have to use a professional duplexer, that means the tuning rod must be from INVAR, which costs approx 60 EUR per kg, you need about half a kilo of it per cavity, so rather count on the price 1200 EUR per 6 cavities. But there is an extreme level of VF from the TV on Králova holi, FM, ATC….so if the converter should work correctly from such conditions, must be implemented accordingly. Jo, and just by the way, OM0OVR successfully aborts ATC device operation, I had to install filters myself because of interference from OM0OVR
It's best to try, how do the converters work on this duplexer.
That they walk really well, I can only confirm from my own experience.Examples:
http://wiki.ham.hu/images/8/8b/Hg9rva_0.jpg
http://wiki.ham.hu/images/0/0a/Hg9rvb.jpg
http://wiki.ham.hu/images/2/24/HG9RVD.jpg
and many others in Hungary and Bulgaria..Of course temperature instability would cause problems due to detuning, I agree with that.
so the wind blows from this Hungarian side……ask Stan OM8AQ, how I rated this duplexer at CQ WW 160m CW this year. The only thing it has in common with the duplexer is the shape, otherwise, the parameters are terrible. That's what a person did, who doesn't know much about duplexers…..perhaps that, that the coaxial cables between the cavities must be of a specific length, that RG58 for this application is therefore maximally usable as a clothesline……and there were many other transgressions. Straight up, I wouldn't even want it for free. And use this for the King's Hall??? maybe not, it wouldn't be worth the shame on such a beautiful hill……
this is a duplexer:
http://lea.hamradio.si/~s51kq/jpg/za-vrh3.jpg
http://lea.hamradio.si/~s51kq/jpg/Krim-6.jpgI have not seen the Hungarian product live, therefore evaluate it at 100% I do not know, I'm just starting from that, that someone is doing it, who also works in this field professionally, but above all from it, how the smugglers work in real life. As for RX sensitivity, they are surprisingly good at it, for the given duplexers to be that bad, as you described them.
to OM1ATT:
ATC = Air traffic control ??? that is, the pair of boxes with TRXs, a table with a PC in the middle and a transmission cabinet on the right side and at the back of the cavity, Cells in the open air halls near the windows? That's what we're talking about?To OM0XA: more about the device, which is in the southwest corner of the same room, ATC is unlucky, that it is on the same floor and in the same building as OM0OVR…. those cavities in the ATC outside the cabinets are just to eliminate problems with the OM0OVR, today, instead of them, an interdigital filter works on one of the cabinets
To OM8ARK: when you look here http://www.om8aq.sk/texty/Trusalova10_11.htm, then you will see Hungarian “groats” in full glory when exploring its properties. Although we didn't use a vector analyzer, it can also be determined with a spectrum analyzer, whether it is usable at all…..IT IS NOT. The joke is in that, that this duplexer has a duplex distance 600 kHz very small dimensions and therefore small Q cavities. Apparently it was intended for greater duplex spacing, I type it on base stations with distance 4.5 MHz. From the three Hungarian hollows you wring suppression with misery 75 dB, same design with 8″ cavity (200 mm internal diameter) can over 125 dB at through attenuation 1 dB (is needed on PI3VNL). With such a duplexer, it is rather a problem to measure it at all, this machine can do it, for example http://www.rohde-schwarz.cz/product/ZVA8%20%282-Port%29.html , but only in the version with direct access to the receiver. Unfortunately, physics cannot be fooled.
If I vaguely remember, so OM0OVR is the original OK0R, OM0OVU also has a similar duplexer and it is not so bad. I would rather look for a fault in the electronics or cabling, or whether there is a reduction in effective sensitivity due to other devices in the building.
