wqzw301

Icom fr-3000 and 4000 is bulletproof at 50watts. Later icom repeaters are not.

Yes my fr4000 does have a cwid. I haven't been in the programming for a while. I have to charge my Panasonic windows 7 laptop, too check the settings. When I can, i will get back yo you

I would like to have a 50watt output. 50 watts put me down to 25 watts... Which I have no problem with low wattage. But I live in the city and twice the wattage gives me about 3-4 more miles. Thanks d

I have an Icom fr-ic4000 repeater. I recently got a great deal on a Celwave 6 cavity pass/notch 100+dB rejection, professionally tuned. It really helps my sensitivity and selectivity on my front end. I have a Henry amplifier continuous, 10 in 70watts out. Which will give me about a 50watts output. Problem is lowest setting on repeater is 25 watts. I do not have, the ability, or want to drop the low setting down to 10 watts and have it realigned. Would a 25watt 4db fixed attenuator, between the tx and amplifier be a fix. To avoid mailing the amp back to henry for an expensive retune, that I might want changed again someday. I have a 50 ft run of 1/2" Heliax Cable to a CommScope DB404. RG400 on the repeater side. Plus, isolator on tx. Please and thank you for any advice.

Hello again, How has your intermod duplexer held up? Mine became very discolored due to the dissimilar metals used in it's construction. I contacted intermod and the guy got pretty mad at me.... Thanks d

They are great! Ham antennas are usually brass wire in a fiberglass random and or not enough ground plane radials. The J-Pole's copper 5/8 inch outer diameter has a wider bandwidth and a lower noise floor for receiving. Plus it's an end fed 1/2 wave that doesn't have any loss, due to, not needing a 50 ohm matching system. Only problem, it is exposed to the elements, like rain....Swr will go up slightly, And as long as it's below 2.0:1, your transceiver, will be good. Also, if you think of it, most commercial antennas are aluminum exposed folded dipoles. The tarnish on the copper will not make a difference. I know someone who had made his own. It worked for 10 years until he took it down to give it to his friend. For the best experience - Don't just click the "buy button" on the website. Contact KB9VBR by email and ask for the j-pole to be tuned for the exact frequency center you want. Also make an air choke with your coax, five or six turns of coax at the base . This will prevent a radiating feedline and prevent distorting the antenna's radiation pattern. Or add sum uhf ferrites to the coax - makes a big difference in swr. I don't think antenna modeling programs take that into account.

I'm planning a new antenna system and mast for my repeater. Got it in my head, that I want to try separate tx / rx antennas. Vertically So, I've looked up the charts and used the CommScope antenna separation calculator. Vertical separation would be 20' - (70db). Which is ok... My rx antenna would be 45' and my tx antenna would be 25'. But does that take into account the isolation I have at the transmitter? I have 3 1db wacom cans on the rx side 2 wacom 1db cans on the tx side, plus a circulator. I will lose 80db without my duplexer. But I can make that up with some more band pass / band reject cavities. So, can I move the tx antenna a little higher up on the mast and make up iso db's at the transmitter, Also my tx antenna will be 6dbd and my rx antenna will be 1/2 wave stacked completely vertical. Please and thank you for any help

Thanks The elements are actually light, it's the pole that's heavy. But the info you sent me, says that it is a reflector and the elements are grounded to it. So I'll save it for another mast, down the rode... Much appreciated, thank you

I have a 40ft fiberglass mast. The aluminum pole is 15lbs. The fiberglass tubing is thick walled 1.75 od. But I can't attach an 18lb antenna (clamps, coax included) onto it. So I though just attach the elements to the fiberglass and lose the heavy metal pole. I have a wide band Laird fiberglass antenna on the mast now... It weighs about 1.5lb. But would like the better reception of the folded dipoles.

Hello, I have a DB404-B antenna. I was wondering if I can swap out the aluminum mast for a fiberglass mast (same Diameter). The 2 bays of elements, coax and matching stubs are pretty lite on their own. So I'm not worried about stability... Does the aluminum mast act as a reflector also? If it is a reflector, will the radiation patterns of each of the lateral dipoles, effect each other. Is the aluminum mast just a mast or part of the antenna system? Please and Thanks for any help

Folded J-pole - It's an end fed half wave, wide band antenna... For me - easier than making a matching stub for a folded dipole. The only reason the folded dipole has a wide band width, is because of the thicker material used ( 1/2 inch aluminum or copper tubing) Which is the same for folded j-pole. I also would think, more loss in using a matching stub, on a folded dipole. And using braided coax to make a stub (which always winds up making noise, because I live in a damp environment , by the ocean) I plan on using superflex So superflex plus folded j-pole for repeater??? Please and thank you for any advice. d

How about a rca to an Amplifier keying relay buffer ?

So - Pin 14 - Open collector=off / 0 V=on Does that mean when the transceiver transmits there is no signal from pin - but while transmitting the pin supplies a signal to open a relay switch or close the switch depending on the type of relay?

Thanks!

Does the shape of a ground plane radial matter? Modeling software deals with lengths maybe even diameter... Ham, commercial, marine antennas - dyi or purchase have tubular or wire radials.... I have a vhf antenna that has (and is the only fault in design) 3 radials maybe 3/8th in diameter. My plan was to add more radials.. But because of set screws, where I would drill and tap 3 more radials, my plan changed to just widening the existing radials. I eventually came to the conclusion I could get more width out of aluminum flat stock than wider aluminum tube. 1.25" width x .25" thickness on all three radials. And I could use the original tapped sockets with aluminum bolts to secure them. I know it won't change the decoupling from the mast,,, but will it change anything, I'm not thinking of? It's unity gain, so I don't think it will effect take off angle? It's not that crucial but now the thought is in my head... and now I'm curios . Any thought's Please and Thank you

Thank you very much!

Thank you! And do you think 25 to ground also?

Does anyone know how or where, I can learn to use the 25 din accessary port to hook up an interface and relay for a linear low noise amplifier. Or even a relay to a bias tee? I know on other transceivers without a keying switch (rca plug) it has been done. It might be a bad idea... but i thought of it, and even if I don't do it, I have to know.... Please and thank you for any help d

Anyone know where to look for a good commercial vhf / uhf diplexer? I have my CommScope 4 bay repeater antenna and marine band vhf antenna on the same mast. I got a good deal on some heliax but only enough for one 40ft run... terminated on both ends with times microwave N connectors. All the diplexers I have found, in endless searches, are for low band or ghz cellular... Repeater-builder warns against the ham products like commet, mfj and diamond diplexers. I did get my hands on supposedly "recent working pull" - Austin Antenna Combiner for UHF, VHF. 130-190 Mhz, 400 - 500 Mhz . Anyone know these, I believe Austin hasn't made these in decades.... based on "internet info".... I do have good isolation on both vhf and uhf sides - band pass / reject on rx/tx sides. And also circulators/isolators on the transmitter sides with harmonic filters. Please and thank you for any advice d

Thanks! PACNWCOMMS Great reply made me feel like i'm on the right track. gman1971 Thanks! Sirio is a great brand - so well designed and constructed. marcspaz Thanks! I do and I will. I just have to relocate the set screw holes. Thanks Lads!

I've been working on this mast design for gmrs repeater and vhf marine radio (possible future vhf repeater) I think it's a good way of optimizing vertical separation with the antennas i have. Icom fr-4000 has 3 receiving cans / 2 transmit cans / transmitter isolator/circulator -plus 6 can Motorola tx/rx duplexer Future vhf will have same amount of db isolation before it's antenna. messi 10 pro coax all n connectors Any constructive thoughts on the plan???

Does anyone know if you can pass a dc current through a splitter/diplexer? For example Comet duplexer cf-4160n vhf/uhf I use a lna with vox at the vhf antenna. I use a bias t to power it through the coax. I've seen some commercial satellite splitters that say dc pass for amplifier but frequencies above 1000mhz and $$$... please and thank you for any help, wqzw301

Check bluemax49er store on ebay.. He might have a usb boot to DOS and a cable with a fdic chip for port driver... Might need to download dos box also. I worked around the problem by buying a cheep used comp on ebay that had widows xp 64 bit... I have like 5-6 Motorola programs running on it now for mobiles and ht's

I just purchased the same one. Pretty good so far. 50watts in 43watts out. 80db of isolation is just as good as my 4 big cans decibel vhf band pass/band reject duplexer. Very impressive. I like the use of silver plating. Nickle makes a mess out of tx'n uhf. Great construction and size.

Great Advice! Thank You KIDPHC . wqzw301