Keyboard Shortcuts
Likes
- Repeater-Builder
- Messages
Search
Re: Occupied bandwidth - (was Windows 7 config)
There is a real problem when relying on training propaganda and brochures.?
With FM analog, you can see some bandwidth, but some voice peak happens at some frequency and another pair of sidebands will pop up with sufficient energy to throw noise into the adjacent channel.? With the different DMR modes, there are very different bandwidth characteristics.? IF you find the lab data that was submitted, at least you might see actual traces rather than a brochure cartoon.? Receiver bandwidth is important too, as a practical matter. The idea of 15/20/25khz does not fly in So Cal where the best hope was for 20khz rx bandwidth.? How do you get 15khz RX bandwidth without changing the TX to +- 2.4khz dev and 12.5khz channel spacing.? Calls for mods for every user radio and attention to frequency accuracy beyond most users. |
Re: Antenna without radials
Richard, the tip off of compromise in the Fong is the use of PVC at all.? It is somewhat lossy, and the fact it de-tunes the antenna
is another indication that it shouldn't be used at all.? I have a ribbon J-pole in PVC that someone gave to me and the problem with it is that 1) it performs no better than a ground plane type.? 2) whatever you tune it to, it changes drastically when you shove it back into the PVC tube.? 3)? I suspect that it changes due to sun and smog damage as well. I get it that it is a lightweight antenna that won't put someones eye out and you could accidentally lose it during the course of an emergency drill and not be crushed and broken hearted. |
Re: Antenna without radials
Ron,
Yes. Agreed. I found similar problems with my Fong, so I will just dedicate it to my dual-band transceiver. It works OK for that. I will revert to my little quarter wave UHF ground plane for the repeater/remote. It has always worked well. It¡¯s just four radials soldered to a N connector chassis mount, with a simple vertical wire for radiating. Has served well for several years. I just thought I¡¯d switch the Fong from repeater to transceiver, as needed. But the Fong gives me TX noise on the repeater. ?You see, the repeater is operational only when I need it. It¡¯s a closed remote here at the house. Richard |
Re: Antenna without radials
There are a lot of things that can screw up your duplex.? Some people will cobble up something just to get on the air and replace EVERYTHING piece by piece to get rid
toggle quoted message
Show quoted text
of a built in problem.? I know what that is like You stated some indication of desense or tx noise at 1W???? And you want to use a transceiver and have it double as a repeater?? I can see problems enough with casual in band operations co-locating with a repeater but you want to share the antenna too?? How do you protect/not protect?? Reminds me of the days of my youth when I sort of duplexed with a scanner.? You might try vertical separation.? Jim makes a great point about end feds - When you place your high voltage node right at the feed point with the balun, choke, connector, transitions, you have the perfect storm for scratchi- scratchi noise.? Not here, no way. Jonny are you kidding?? Bring back foil and coat hangers?? Jam yourself?? Not a good idea to jam your neighbors though unless you think we all need to be punished.? It is also known as Sh**ing the Bed.? Some will think you are serious.? It is some kind of psychosis or mental dysfunction to give in to self inflicted misery just because you saw __x__ doing it.? It is a common tactic to psy-op entire populations to render them self-destuctive so they could never mount a defense to any attack or enslavement.? Prepare your mind so as not to fall for it like the others.? We are seeing more and more a dumbing down of everything.? People are going to ham class mills that don't teach anything but Q & A so people are dumped en masse into the ranks with no clue or appreciation of the knowledge that was acquired over the last 150 years.? People are graduating from schools with degrees in confusion.? It all spells a return to global feudalism where ignorant and pompous "leaders" lord over serfs and the hard won knowledge of the ages is lost.? On Sat, Nov 12, 2022 at 05:24 AM, Richard P wrote:
|
Re: Antenna without radials
¿ªÔÆÌåÓý
Richard,
Two issues with a Fong style J-pole are coupling to the mounting pole/surrounding metal, and proper decoupling of the feedline.? I have made slightly different variants that address these issues and have had good luck.? Any metal structures within???wave
radial distance of the stub or radiator will drastically affect tuning and pattern if proper mounting and decoupling are not done.? His kits do not take this into account and leave it to the builder to fix.? Also, using different pvc (which I do due to availability)
than the thin wall he calls out will affect tuning. All that being said, not the best antenna for side mounting on a tower or top mounting on any commercial or tall tower.? Not bad though for temp/portable operations, or top mounting on small structures or
roofs when a high gain colinear is not available.? Good luck with your project.
73,
Ron
From: [email protected] <[email protected]> on behalf of Richard P via groups.io <wb5nen@...>
Sent: Saturday, November 12, 2022 1:24 PM To: [email protected] <[email protected]> Subject: Re: [repeater-builder] Antenna without radials ?
Thanks. I¡¯m fairly familiar with repeaters. Built and maintained three of them. Built two remote bases. Duplexed Micor mobiles. Resoldered bad copper connections inside noisy PD Stationmasters. Etc.. Just having a problem with the Fong (which, BTW, for me, was very, very fussy to tune). I think I will just have to go back to my UHF quarter wave for the UHF/HF remote base. Hard to argue with success. And, unlike most repeaters, I don¡¯t want much coverage¡just a mile out, or less.?
|
Re: Antenna without radials
You are very wise to be suspecious of questionable antenna "guidance" that percolates up on this email list from time to time. On Sat, Nov 12, 2022, 10:30 AM Jonny Tomlinson KF6PHX <jstlink@...> wrote:
|
Re: Occupied bandwidth - (was Windows 7 config)
Gang,
The chart showing the ICOM D-Start bandwidth / PSD claims is nice with one exception...? It doesn't tell you how far down the sideband energy is relative to the reference carrier.? Without that information it's just a pretty picture.? Am I missing something? Burt, K6OQK ![]() |
Re: R1225 Ribbon Cable set
All, I appreciate everyone's responses and I do understand that the repeater will function without the control head, and that a GM300 head will serve as a simple programming interface, however that's not what I was asking.? I'm asking for a cable set because I would like to make this particular desktop repeater function as is was originally designed, with local control.? I thought I'd start here as the usual auction site only has one option, and the owner wants more than I paid for the repeater. My next step will be to try and source the header pin connectors and make my own cable set. Thanks all, Jeremy? On Fri, Nov 11, 2022, 8:09 PM M M <wa6ilq@...> wrote:
|
Re: Antenna without radials
¿ªÔÆÌåÓýI love it...I think all the variations of antennas provide a lot of fun and experimentation in the hobby. Whether they are not so perfect antennas or whatever is null and void. Different folks can only use certain antennas at their location. I say keep building imperfect antennas,use rg8x coax on hf,put lmr400 on uhf and rock on! This hobby needs fun and experimentaion...not perfection! LolSent from my Verizon, Samsung Galaxy smartphone Get From: [email protected] <[email protected]> on behalf of Jim Aspinwall <Jim.No1PC@...>
Sent: Saturday, November 12, 2022 7:19:23 AM To: [email protected] <[email protected]> Subject: Re: [repeater-builder] Antenna without radials ?
The whole end-fed, Zepp, Ringo, j-pole genre are known stray RF, RF on coax, common-mode, choke/don't choke, ground/don't ground bizarreness.? Just not suitable to cohabitate a multi-radio situation.? ?The j-pole folks refuse to produce EZ-NEC models, but W8JI and others have covered them in detail.? Worse the dual-band variants.? Not going up at my shack. 'the' end-fed half-wave for HF is all the rage now, since the G5RV and OCF 'great' antenna days.? Odd thing is there are half a dozen "all band" end-fed variants, with counterpoises, etc.? Fun to watch.?? ? |
Re: Antenna without radials
The whole end-fed, Zepp, Ringo, j-pole genre are known stray RF, RF on coax, common-mode, choke/don't choke, ground/don't ground bizarreness.? Just not suitable to cohabitate a multi-radio situation.? ?The j-pole folks refuse to produce EZ-NEC models, but W8JI and others have covered them in detail.? Worse the dual-band variants.? Not going up at my shack. 'the' end-fed half-wave for HF is all the rage now, since the G5RV and OCF 'great' antenna days.? Odd thing is there are half a dozen "all band" end-fed variants, with counterpoises, etc.? Fun to watch.?? ? |
Re: Occupied bandwidth
A lot of people tend to forget that EVERY transmitter has sideband noise. Regardless of the actual transmitted mode, there will be noise on either side of the carrier. In an FM signal, this noise extends into the squelch range of receivers on adjacent channels. When Texas was considering 15 k vs 20k splits in the 80s, I did testing with Micor receivers on the bench and proved that 20 kilohertz was far superior to 15 spacing. The squelch was not affected at 20 kilohertz even with strong signals but at 15 it would cause issues big time along with desense of the desired channel. Testing with a Spectrum repeater that was local to me, I could get 15 kHz off with a dead carrier w/no modulation, several miles away with a 30 watt mobile and squelch the receiver up on noisy signals. The receiver in the repeater was an SCR200 which used the typical Motorola MC3357 IF chip and had 15 kilohertz filters in it! Same tests at 20 caused no ill effects. Not everybody runs high-end RF gear on a repeater. My testing was part of the reason why Texas went 20 kilohertz back in the 1980s. And I'm damn glad we did. I even had Louisiana vote twice to go 20 kilohertz when I served on the board of directors of the Louisiana council. But unfortunately some die-hard idiots in New Orleans refused to move and the frequency coordinator gave up trying to change the state. Right now it's a mix of 20 and 15 across Louisiana. Maybe one day they'll join the 21st century.. But we're talking Louisiana here .... Almost as bad as Mississippi ? I'm still waiting for a decent national band plan on 6m. The current plan is based on 50+ year-old radio technology! Really? When the ARRL took a poll back in the '90s, the results showed that majority wanted to stay the 1MHz split or go to the -1.7 WWARA plan... But the representatives from California and SCRRBA shoved that stupid 500 kilohertz outdated plan down the VRAC's throat.. I had a heated phone conversation with the West Gulf director about it and he was upset about it as well. But he said it was a political move and nobody wanted to argue against it. Well, that's BS! It's time 6M FM got into the 21st century as well.. I bet a lot of you don't even realize why 52.525 is such an oddball channel! If you do then you've been around as long as I have? ? Chris WB5ITT? On Sat, Nov 12, 2022, 8:45 AM John <jhaserick84@...> wrote:
|
Re: CPS programming issues w/cdm1250 for repeater with ID-O-MATIC v4
Same exact story here.... M1225's up for 3 years, then failed.? Replace one radio, no go.? Switched over to CDM1550's and worked great for 6 months, then not.? Sold all the M1225's and still working on the CDM's.? ?bi7jta.org has some instructions... So, does RB, but can't find them right now...
|
Re: Occupied bandwidth - (was Windows 7 config)
What might follow to your comments, Neil, is that as far as additional transmitter bandwith added by the PL component I think it is not really the additional say +- 0.7KHz, but more like just the PL frequency say +_0.15 KHz. To back that up, once a fellow ham and I did a crude over the air test using a Micor PM modulated transmitter with and without PL. We were about 40 miles apart and he was hearing us with about 50 % noise and his squelch was set such that for every 10 times I said a loud "five", his receiver would squelch out on my voice peak 3 out of 10 times. That did not vary with or without PL. Ever since then I set peak dev on the initiatiing mobile, base or portable to 4.8 KHz assuming perfect deviation symmetry with less than 100cps frequency drift, and then disregard the 0.7 KHz PL deviation where the service monitor would read +_5.5 KHz (unless it was set up for only sensing 300-3000cps. With these settings maximum range is achieved, with just a slight occasional increase in distortion over +-3KHz dev on voice? peaks(how a lot of receivers seem to be rated when measuring audio distortion).
John W1GPO
|
Re: Antenna without radials
Thanks. I¡¯m fairly familiar with repeaters. Built and maintained three of them. Built two remote bases. Duplexed Micor mobiles. Resoldered bad copper connections inside noisy PD Stationmasters. Etc.. Just having a problem with the Fong (which, BTW, for me, was very, very fussy to tune). I think I will just have to go back to my UHF quarter wave for the UHF/HF remote base. Hard to argue with success. And, unlike most repeaters, I don¡¯t want much coverage¡just a mile out, or less.?
|
Re: Telewave TPRD-1554 Won¡¯t Tune To 600KHz Notch
Jared. These duplexers came in 2 different splits. Low band and high band vhf, and had the same problem as you did. The high band will not go down below 148 MHz and telewave told me at that time that it will not work.
toggle quoted message
Show quoted text
I gave up and used these duplexers on the commercial band. Works very well ... Millin ----- Original Message -----
From: Jared Smudde <computerwhiz02@...> To: [email protected] Sent: Fri, 11 Nov 2022 19:02:25 -0700 (MST) Subject: [repeater-builder] Telewave TPRD-1554 Won¡¯t Tune To 600KHz Notch I¡¯ve got a set of Telewave?TPRD-1554 VHF duplexer sitting on my bench. The duplexer is 3 years old, spent 2 years in service on a 3mhz split in the 150MHz range before being removed a year ago. Upon trying to retune it to a 600KHz 147MHz range, we ran into an issue tuning the notches. On each of the passes, one cavity had no issue tuning the notch to a 600KHz split but the other cavity wouldn¡¯t even come close. Both passes exhibit the same behavior. We got ahold of Telewave support and we were told one of the pass low/reject high loops had to have an extra capacitor on it to achieve the 600KHz split. The other loop on the pass low side could remain the same. When asked about the pass high/reject low issue, they told us that no changes have to take place to the loops, it should do the 600KHz split with no issues. Except it still doesn¡¯t work. We¡¯re waiting on the parts to fix up the pass low loop but in the mean time, has anyone seen this issue before? |
Re: Antenna without radials
The whole repeater and duplex operation thing will show you what doesn't work.? There is a lot to that, but the fewer
the contact points, the less noise.? Think hardline, heliarc and no dissimilar metals throughout the antenna system.? Make sure no moisture can get into anything.? Make sure no hardware will rust or be galvanic. It sounds like you are experimenting and maybe you don't have test equipment to be able to tell a great deal.? Be aware that other things in the area of your antenna can also generate noise when you transmit, destroying your duplex. The Ed Fong thing seems to be a well hyped project, but I haven't seen any subjective testing.? It is well hyped to newbies as the J-pole once was.? IF well constructed with the proper coax and connectors and antenna hardware, it might work well for a localized antenna, but I haven't tried one. |
Re: CPS programming issues w/cdm1250 for repeater with ID-O-MATIC v4
You don't say if it was the receive or transmit radio that quit. You also don't describe if the radio that failed, completely failed or just stopped transmitting or receiving. Depend on the situation you could swap the receiver and transmitter, with the correct programming and keep going. Or . . .
toggle quoted message
Show quoted text
Although I don't know that much about the CDM other than they are not really that much different. At least for troubleshooting, you could use the M1225 that is working with a CDM and work that way to try to figure out what is going on. Otherwise, I would just check all of your wiring good. You shouldn't have had to change any wiring, but you could have a band connection or broken wire. Just start in with basic trouble shooting and work your way through it. What do you have for test equipment to work with? Mick - W7CAT ----- Original Message -----
From: "Mike via groups.io" To: [email protected] Sent: Friday, November 11, 2022 09:42:58 PM Subject: [repeater-builder] CPS programming issues w/cdm1250 for repeater with ID-O-MATIC v4 I have had a GMRS repeater active running 2 Motorola M1225LS radiosusing an ID-O-MATIC 4 controller and everything was working very good. Unfortunately one of my M1225LS radios failed, so I thought I would use a couple CDM1250's I have that are in excellent condition. I called Dan who builds the ID-O-MATIC controller and he said that the wiring configuration that was setup for the M1225LS radios would be the same for the CDM1250's. So I hooked everything up. Opened up my CPS software, and reprogrammed the CDM1250's to work (what I thought) as a repeater. I am able to key the repeater with my handheld via the RX radio, and the ID-O-Matic keys the TX radio just as it should. The problem IS........ There is no audio passing through the controller through the TX radio. I have tried, and tried to play around with the settings to get it to work with NO LUCK. I am not at all a wizard with the CPS software by no means. (And I'm sure I have things messed up with both TX, and RX radios). Anyone have a working code-plug for the CDM1250 that will work using an ID-O-MATIC controller? I am at my wits end. All help will be GREATLY APPRECIATED! -- Untitled Document |
CPS programming issues w/cdm1250 for repeater with ID-O-MATIC v4
Mike
I have had a GMRS repeater active running 2 Motorola M1225LS radios using an ID-O-MATIC 4 controller and everything was working very good. Unfortunately one of my M1225LS radios failed, so I thought I would use a couple CDM1250's I have that are in excellent condition. I called Dan who builds the ID-O-MATIC controller and he said that the wiring configuration that was setup for the M1225LS radios would be the same for the CDM1250's. So I hooked everything up. Opened up my CPS software, and reprogrammed the CDM1250's to work (what I thought) as a repeater. I am able to key the repeater with my handheld via the RX radio, and the ID-O-Matic keys the TX radio just as it should. The problem IS........ There is no audio passing through the controller through the TX radio. I have tried, and tried to play around with the settings to get it to work with NO LUCK. I am not at all a wizard with the CPS software by no means. (And I'm sure I have things messed up with both TX, and RX radios). Anyone have a working code-plug for the CDM1250 that will work using an ID-O-MATIC controller? I am at my wits end. All help will be GREATLY APPRECIATED!
|
Re: 6' base station cabinet needed in the Ozarks
¿ªÔÆÌåÓýI have two GE Master II 72¡± upright cabinets with both front and back doors and a fan in the top to exhaust heat. ? Just take them away from San Carlos, California ¨C San Francisco Bay Area. ? Also have a third GE MASTER II cabinet with a very clean UHF 100 Watt UHF repeater and Power Supply with repeater metering kit for the top / front of the cabinet.? It is complete with doors also. ? PL decode and encode included in repeater. ? Come haul it away. ? Bill W6CBS ? From: [email protected] <[email protected]> On Behalf Of Randy Kohler KI4EZU via groups.io
Sent: Friday, November 11, 2022 6:46 PM To: [email protected] Subject: Re: [repeater-builder] 6' base station cabinet needed in the Ozarks ? I have a 6ft open frame rack here in the tri-cites, and a small 3- inch cabinet with a glass door. ? ? ? On Friday, November 11, 2022 at 06:11:41 PM PST, Karl Shoemaker <srg734@...> wrote: ? ? Wish we know truck drivers that go from West to East in the US for these big items going around.
Randolph C Koehler KI4EZU AE VE? ARRL EWA DISTRICT 8 EMERGENCY COORDINATOR KI4EZU {at} YAHOO {dot} COM |