Re: [Repeater-Builder] Re: Flat Audio
Again, controlling deviation has nothing to do with the audio components of the signal. The audio does not change based on the deviation. (short of audible distortion if it exceeds the passband) I agree it is your responsibility to make sure that your TX does not overdeviate, but there is absolutely nothing you can do to change the overdeviation of the user's radio. (short of telling him to fix it) Let's keep the discussion of the audio limited to the audio and not add more issues to an already complex problem. All this said, there is nothing in Part 97 that limits your deviation. This is likely why so many radios are overdeviated from the factory - a problem which I acknowledge, but do not see a relationship to audio. Many radios have crappy audio, too. I've been evaluating a new commercial unit for a manufacturer that sounds worse than any ham radio I've ever heard. Yes, it's understandable, but the audio is tinny and sounds like crap compared to other current commercial radios. Yet, the deviation is fine. ;- Joe M. N9WYS wrote: Gentlemen, I've been sitting in the wings following this thread, and I think it's time I added my 2¢ worth... First of all, I'm not in the business, but I am in the hobby. If I read Part 97 correctly, the FCC requires that I, as the control operator/trustee of a repeater, ensure that **my** repeater emissions are in compliance with said Rules (97.307, inclusive). In doing so, the FCC has mandated that I fix the problems caused by users who transmit with too-wide a deviation. Yes, the individual repeater user is responsible for THEIR emissions on the input frequency, but it is my opinion that I am responsible for the ones that come out of my repeater. If someone transmits in with too much deviation, and I retransmit such product back out on my repeater, then **I** am at fault. (In addition to the user on the input.) To prevent this, I set max deviation on my 440 repeater at about 4.5 kHz including any CTCSS mixed in with the voice, and the deviation on my 900 machine at about 2.2, IIRC. (In actuality, the deviation on my 900 machine is a bit low - it requires more volume control twist on the user's end than it probably should... but that's another discussion.) This keeps me within the bandwidth of the frequency allocation, and the FCC off my back for causing adjacent-channel interference. (Forgive me if I'm not using the proper technical phraseology/wording - I'm merely trying to get my point across.) Nor does this ...intentionally make properly set-up radios sound worse. At least the output wont be over-deviating. What I think Skipp was trying to say (and forgive me, Skipp, if I'm putting words in your mouth) is that a LOT of radios coming from the Pacific Rim are coming in with the deviation set right at, if not a bit higher than spec. I see this when I switch between commercial gear which I have converted for Amateur use, and the stuff I own that is Amateur out of the box. (And all of them are as guilty as the next - Icom, Yaesu, Kenwood, et al.) I get told to back off the mic because my audio is too hot, or that I'm sounding a little fuzzy. (Of course, that is until I adjust it down... I dont personally have the necessary technical equipment to be able to adjust radios 24/7, so when I detect a problem, I borrow the necessary item (be it a Service Monitor, or other). On the other hand, I have to agree with Joe when he says that some hams are overly obsessed with the quality of the audio emanating from a given repeater... to a fault in some cases, as far as I'm concerned. I have one user on my machine that complains **every time** ANYONE is less than full quieting into the machine, or when the machine is less than full quieting on his radio. Forget the fact that he can successfully complete his communication - he isn't happy with the audio. I think that if I provided him with repeater output audio direct-wired through Sennheiser studio-quality headphones that he'd still complain. Let him try HF SSB just once... For now... 73 de Mark - N9WYS (Also GROL) -Original Message- From: Repeater-Builder@yahoogroups.com On Behalf Of mch skipp025 wrote: Actually, 'flat response' is better. Since the de-emph/pre-emph changes the audio intentionally, the term 'processed audio' is more applicable to such a repeater. I and probably most of the two-way radio industry do not agree. It's really about what part of the hardware you are actually talking about. Well, most of the two-way industry doesn't really care about repeater audio the way hams do. If you can understand what the other person is saying, it's good enough. There is even one commercial repeater near me that has open squelch on the tail. Yea - that sounds good. If it sounds dull and weak, that is because the USER RADIOS made it that way. A properly set up repeater will not alter the audio at all.
Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio)
Commercial radios also used fixed values. The Micor is one example of fixed values for tone deviation. Chuck WB2EDV - Original Message - From: Mike Morris WA6ILQ [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, March 14, 2007 11:37 PM Subject: Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio) At 07:23 PM 03/14/07, Eric Lemmon WB6FLY wrote: Nate, Several years ago, I chastised ARRL Labs for failing to report the basic 2-way radio performance parameters of 12dB SINAD sensitivity, voice deviation limit, CTCSS deviation limit, and center frequency accuracy. I did not get a satisfactory answer, but I suspect that there is a reluctance to disparage the performance of name-brand Ham radios. QST survives on the ads. The league doesn't want to risk the revenue. As the wise man said, he who has the gold makes the rules. Nearly every Amateur 2m radio I have tested has CTCSS deviation far in excess of the EIA/TIA recommended level of 750 Hz, and that level is not adjustable in most radios. Pots cost more than fixed resistors and that would reduce the profits.
[Repeater-Builder] motorola P020
dear all i have a problem of Alignment of motorola P020 .. when i read it to access service mode it has request password ,so i enter the password i think it ,but it's re request patchfile or something ?? i use Alfa series RSS ,,, thanks Regards Khaled - Expecting? Get great news right away with email Auto-Check. Try the Yahoo! Mail Beta.
Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio)
2.5 kHz channel spacing? Where is that used? It's not in the commercial USA market. Or did you mean 7.5 kHz? Joe M. James wrote: And most ever ICOM (I - It, C - constantly, O - over, M - modulates) over modulates. Every one I set my hands on will do 6.5Kc (never mind the poor stability). I personally love the Kenwood TM271. I have one, and it holds up to every claim ... and makes the same specs as the commercial (part 90) stuff. It even does 2.5 KHz channel steps to comply with modern narrow band channel planning (not that narrow band is really in use in the amateur community yet ... except one of my 2 meter machines). James WJ1D
Re: [Repeater-Builder] Re: Flat Audio
skipp025 wrote: mch [EMAIL PROTECTED] wrote: Well, most of the two-way industry doesn't really care about repeater audio the way hams do. And your point is..? The point is that you cannot compare an industry where 'intelligible is good enough' is the standard for most to an industry that thrives on 'the best you can get'. If you can understand what the other person is saying, it's good enough. Just depends on who owns and operates the equipment. Crappy audio is easily understood but not good enough for a lot of ham and commercial radio owner/ops who actually care what things sound like. True, there are some in the commercial world who care about having a good sounding system. But the vast majority do not. You completely missed the point. It's not up to the repeater to fix user problems. We don't depend on the repeater to fix typical user radio issues. But we configure our machines to do a good job cleaning up what we often experience, which is often well over deviated radios. As I said in another post, deviation and audio reproduction are mutually exclusive with the exception of a radio which exceeds the receiver passband and introduces distortion. If you run 4 kHz deviation vs 5 kHz, your audio spectrum is proportionally identical. If you had tinny audio at 4 kHz, you will have tinny audio at 5 kHz. Yes, it would be nice if all hams could properly maintain their equipment. Wouldn't need to if hams would expect or demand new Amateur Radio Equipment be sent out with more realistic deviation and audio levels set. True. It would be nice if they could install a 3-wire CTCSS encoder that has +, ground, and audio out. Not for me... where possible I'd want my encoder to include additional functions for reverse burst. Again, you missed the point. If someone cannot find 12V, ground, and audio, they certainly aren't going to be able to find 12V, ground, audio, PLUS PTT in and out. It would even be nice if all hams knew how to actually operate their equipment. --- But enough with fantasy-land --- Yep... you're getting a little sideways again. Not really. The inability to operate goes directly to improper maintenance and overdeviation or distortion. My FT736, if not adjusted properly with user controls, will easily overdrive the TX and sound like crap. In the real world, if someone's radio sounds crappy, it needs fixed by someone or the radio will get a (well deserved) reputation as a POS and people need to know to not buy that model. But an over deviated new radio doesn't sound crappy in the typical operators hands. It often sounds pretty darn good/loud. So the mfgrs keep sending them out hot and few people complain about it. And repeaters which 'fix' the problem for them doesn't help, either. Then there is the adjacent channel interference they create. There is nothing you can say that will convince me that any repeater can solve that problem. Yes, we had clinics, too. But, many hams feel that if they are understandable, that is 'good enough'. Of course, people who compensate for their shortcomings in the repeater only serve to accommodate the problem rather than solve it. We have to be realistic Joe. But you have some solution for the problem of over deviated radios that doesn't torque off the user? I don't care about them being torqued off. They just should be aiming it in the right direction - at the manufacturer who misaligned their radio. A good ham should want their radio to be in proper working order. If they get mad, let them have one that sounds bad. But, don't try to compensate for those who don't care what they sounds like. They won't appreciate it anyway. Again this is the problem in today's ham radio - people are so worried about hurting the feelings of others they won't even tell them when they need their radio fixed. That's why some people feel it necessary to compensate for them rather than be honest with them. Then maybe the passband of the receiver should be tightened up more. When those people are choppy on all the repeaters, they might consider getting their radio properly serviced. In the real world... most users never really experience popping in and out of he receiver for a number of reasons. When visitors to our machines pop in and out of the receiver... we tell them to turn the mic sideways and talk across it. We also explain why and a few of them actually get their radio serviced or remember to talk across the mic when they pop in and out of repeater receivers. And that is much closer solving the problem, not the symptom. It has the effect of lowering the user deviation through proper usage techniques. Now, if they would only really limit the deviation rather than doing it through operating procedures, that would be ideal. But, again, too many hams are appliance operators only. Of course, nearly everyone with experience knows that in time of emergency, nearly all compensation
Re: [Repeater-Builder] Re: Flat Audio
Most times when we hear or read about the term flat audio... our attention is normally directed toward the demodulated audio sections of the repeater hardware. Or at least our attention should normally be directed at the demodulated audio stages. When you look at the global repeater audio through-put as being flat you should probably learn to call it transparent. A much better label, which doesn't give people information converse to conventional or traditional two-way radio industry terms. When you say flat audio... we're normally thinking in and around the repeater demodulated audio stages. In other words, we're going to head for the 'Line Out' pin, and work backwards from there. That will be 600 ohm audio designed to be fed through a phone line and to a remote console. When you say transparent to voice audio we're normally thinking about the overall operation of the repeater system. Anymore, the repeat audio path in a new repeater is a factory path. The most a technician/installer can do is set levels. And it's usually done with soft-pots. -- Jim Barbour WD8CHL
Re: [Repeater-Builder] Re: fixed-audio?
Nate Duehr wrote: A... We haven't had a good What kind of audio is it REALLY mini-debate on the list in quite a while... good to see it again... heh. I agree with Bob that people keep mixing the term flat with discriminator and that's just downright confusing to new folks. Some of us understand what you meant to say, but it's the mix of the terms that throws people. I've always called it raw discriminator audio. I read it in a book somewhere ;c} For any newbies reading along... if you find this discussion confusing -- don't worry. It is. Don't worry about it. In fact, we'll give ya the real deal here below... something you can actually DO/USE... You won't need to fully understand this unless you find out that you need to FIX it... then you'll have to dive in with both feet. To find out if you need to FIX it... Grab a radio. Put it on a good outside antenna. Listen to a station that's both full-quieting into your repeater and also into your location on the input. Hit the reverse button on your rig while they're talking. Just to add to that-use a mobile, not a handheld, with a good speaker, not these little 'jap-trac' 1-2 speakers. Plug a good 4 Motorola, GE, EFJ, Midland, Kenwood, etc speaker in to it. And NOT a 12 bass reflex speaker either... If they sound EXACTLY the same through the repeater as they sound on the input... you built your repeater right! Kick back with a beer and enjoy the never-ending terminology debate on the list knowing that you did yours correctly. If the two signals DON'T sound exactly the same, start reading -- and learning... and start deciding HOW the person sounds different: Are they quieter or louder on one or the other (deviation level, a limiter in the radio, or levels are set wrong somewhere)... ? More sleuthing required. Or do they sound tinny or bassy (uh oh - you're going to have to figure out this pre/de-emphasis thing... that or you've got a filter acting funny... or you have a radio with a really goofed up audio response somewhere... maybe you're using a MIC input or... well, there's lots of possibilities...)? If you find yourself with a repeater that is NOT right -- post your EXACT setup to the list including where you're taking audio from on each radio, whether your controller supports doing internal pre/de-emphasis, etc -- the model numbers and where you tapped audio from are usually PLENTY of info for most of us here to help you out. And if you can describe your setup accurately -- there's virtually no doubt the gurus here can help you make it sound RIGHT... the terminology and arguments will fade away and we'll all stop arguing and help you out! (GRIN) So, distilling it down to what's important here... Here's my public service announcement for the day... If users sound the same on the input and output... you did it right. If not, post questions and start figuring out how to get there. Nate WY0X Nicely said, Nate! -- Jim Barbour WD8CHL
Re: [Repeater-Builder] Re: fixed-audio?
Nate Duehr wrote: Sure would be nice to see ARRL labs do a shootout of repeater controllers with tests like this one... they spend days and days (and page after page) testing out $10,000 HF rigs... And people wonder why I don't join... If I could afford to blow $10K on an HF pos rig, I wouldn't be working here-or anywhere else for that matter. -- Jim Barbour WD8CHL
Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio)
Eric Lemmon wrote: Nate, Several years ago, I chastised ARRL Labs for failing to report the basic 2-way radio performance parameters of 12dB SINAD sensitivity, voice deviation limit, CTCSS deviation limit, and center frequency accuracy. I did not get a satisfactory answer, but I suspect that there is a reluctance to disparage the performance of name-brand Ham radios. That's probably because they don't know what those terms mean. They have their collective heads so buried in HF SSB that, to most of them, anything above 30 Mhz, and has a squelch control, isn't ham radio. Many still feel that CTCSS access on a ham repeater should be banned. -- Jim Barbour WD8CHL
Re: [Repeater-Builder] ICM Crystals Off Frequency?
Doesn't the MSR-2000 use the crystal element that has an internal range adjustment? Seems to me that when we converted one about four years ago, it wouldn't warp high (maybe it was low) enough. We opened the thing up and found a trimmer in there, moved it slightly and put it back together. We were then able to get it on frequency with the external adjustment. I might have been a tuning slug...I've slept too many times since then so I don't remember. However, I do remember opening the element and tweaking it. de WD7F John in Tucson - Original Message - From: Robin Midgett [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, March 14, 2007 10:02 PM Subject: [Repeater-Builder] ICM Crystals Off Frequency? Either I'm missing something or ICM sent me defective crystals. I ordered two pairs of crystals to put a MSR-2000 repeater on 147.105 Tx / 147.705 Rx. I've tried both Tx crystals in the KXN1095A channel element only to find the frequency to end up ~36kHz. high. The crystal itself is putting out energy at 12.26180 MHz.; it should be 12.25875 MHz. The bag label indicates them to be cut for 12.25875, but they don't oscillate at (barely even near) that frequency. Should I have to pad the new crystals with a cap to net them on frequency? If so, what value? Thanks, Robin Midgett K4IDC VHF+ Glutton EM66se Yahoo! Groups Links -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.446 / Virus Database: 268.18.11/721 - Release Date: 3/13/2007 4:51 PM
Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio)
You're right, at least right about one we converted to 220 a year or so ago http://home.comcast.net/~micorrepeater/ . I don't know the model number, but it's a hi-band VHF 100W continuous machine in the tall cabinet. How do you handle the IDC adjustment? We ended up having to adjust IDC for 800 - 1K PL deviation and left it there, setting the maximum deviation via the controller. I considered figuring a way to modify the PL card or the exciter so that the level could be adjusted independently of IDC. That puppy was a real learning experience for us novices. de WD7F John in Tucson - Original Message - From: Chuck Kelsey [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Thursday, March 15, 2007 3:44 AM Subject: Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio) Commercial radios also used fixed values. The Micor is one example of fixed values for tone deviation. Chuck WB2EDV - Original Message - From: Mike Morris WA6ILQ [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, March 14, 2007 11:37 PM Subject: Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio) At 07:23 PM 03/14/07, Eric Lemmon WB6FLY wrote: Nate, Several years ago, I chastised ARRL Labs for failing to report the basic 2-way radio performance parameters of 12dB SINAD sensitivity, voice deviation limit, CTCSS deviation limit, and center frequency accuracy. I did not get a satisfactory answer, but I suspect that there is a reluctance to disparage the performance of name-brand Ham radios. QST survives on the ads. The league doesn't want to risk the revenue. As the wise man said, he who has the gold makes the rules. Nearly every Amateur 2m radio I have tested has CTCSS deviation far in excess of the EIA/TIA recommended level of 750 Hz, and that level is not adjustable in most radios. Pots cost more than fixed resistors and that would reduce the profits. Yahoo! Groups Links -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.446 / Virus Database: 268.18.11/721 - Release Date: 3/13/2007 4:51 PM
Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio)
Yikes!. You mean that spark gap is dead! Lance N2HBA - Original Message - From: Jim B. To: Repeater-Builder@yahoogroups.com Sent: Thursday, March 15, 2007 8:59 AM Subject: Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio) Eric Lemmon wrote: Nate, Several years ago, I chastised ARRL Labs for failing to report the basic 2-way radio performance parameters of 12dB SINAD sensitivity, voice deviation limit, CTCSS deviation limit, and center frequency accuracy. I did not get a satisfactory answer, but I suspect that there is a reluctance to disparage the performance of name-brand Ham radios. That's probably because they don't know what those terms mean. They have their collective heads so buried in HF SSB that, to most of them, anything above 30 Mhz, and has a squelch control, isn't ham radio. Many still feel that CTCSS access on a ham repeater should be banned. -- Jim Barbour WD8CHL
Re: [Repeater-Builder] Re: Flat Audio
skipp025 wrote: mch [EMAIL PROTECTED] wrote: In the real world, if someone's radio sounds crappy, it needs fixed by someone or the radio will get a (well deserved) reputation as a POS and people need to know to not buy that model. But an over deviated new radio doesn't sound crappy in the typical operators hands. It often sounds pretty darn good/loud. So the mfgrs keep sending them out hot and few people complain about it. Part of the problem has been poor audio recovery/limiting in the receivers. While a commercial-grade rx will start distorting and dropping squelch at around +/-5.5 to 6 Khz deviation, many ham rigs will accept as much as 8-10Khz of deviation. And of course, a tx running that much will sound louder. I am finding that newer rigs *are* much better in this regard. But I remember the Heath 2036, and one guy who set up a maggiore repeater by ear using his heath 2036. I easily saw peaks as high as +/-15 to 20 Khz on the scope. But it sounded good to him-no one else, but he liked it. -- Jim Barbour WD8CHL
RE: [Repeater-Builder] Re: fixed-audio?
Real world transmitters always have limiters. Those DO change flatness. Just look at the EIA/TIA specication for testing transmitter pre-emphasis. The test is not run at system deviation. It is not even run at 60% of system deviation. It is run at 20% of system deviation. [that's +/- 1 KHz deviation for 5 KHz systems] Run the test at 20% into a modulation analyzer and you get a nice 6 dB per octave line from 300 to near 3000 Hz. Run it again at higher deviations and see what the limiter does to your nice straight line - the pre-emphasis curve hits the limiter at progressiviely lower and lower frequencies as you increase the deviation. The result of this fact is going to alter the audio characteristic going through your repeater. It's one reason why level setting is so important. It is also a significant reason why it's difficult to get a repeater to sound like simplex. That agument loses a lot of its bang when you consider that the audio was already limited POST-PREMPHASIS in the user's radio. Assuming the preemphasis curve in the user's transmitter is the same as the deemphasis/preemphasis curve in the repeater itself (i.e. in terms of slope or equivilent RC time constant), then the repeater will not alter the end-to-end response. Another post suggested checking the frequency response of your repeater. Definitely - do that. Try it a various deviations. You may be surprised at how ugly it gets. Seeing frequency response change as you get into limiting is completely expected; ugly seems rather harsh. If you don't see an apparent knee in the frequency response plot where there is a transition from positive slope to zero slope as you approach system deviation, then the limiter isn't working! Bottom line: limiting after preemphasis results in a reduction in the noise-limited dynamic range at higher frequencies; that's a natural byproduct of a process which originated in the user's radio. The repeater, following the same preemphasis/deemphasis curve as the user's radio, has no further affect. Any variation or degradation in frequency response, S/N, THD, etc. as the audio passes through the repeater is solely due to imperfections in the design, implementation, or medium, not the preemphasis/deemphasis process within the repeater since the two are receiprocol. --- Jeff
RE: [Repeater-Builder] Re: Flat Audio
Most two-way radio people never use the term flat audio repeater. We would assume most standard voice audio repeaters operate as the mentioned so the flat audio repeater has never really been applied by Industry as a real description. Some Amateurs seem to want to apply the label and confuse the heck out of everyone. It appears that these people have done a pretty good job... To the Industry... the proper term is more likely to be transparent. Perhaps Motorola, not hams, created the flat audio monicker. The flat audio board came standard with the exciter in Micor PURC stations (it took the place of the PL deck). Its purpose was similiar to that of flat audio mods hams do - it got around the blue blob mic processor which normally provides preemphasis/clipping/LPF. Regardless, it's confusing as heck to many newcomers. --- Jeff
Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio)
mch wrote: 2.5 kHz channel spacing? Where is that used? It's not in the commercial USA market. Or did you mean 7.5 kHz? Joe M. FWIW-He said channel steps, not spacing. James wrote: It even does 2.5 KHz channel steps to comply with modern narrow band channel planning -- Jim Barbour WD8CHL
Re: [Repeater-Builder] Re: fixed-audio?
Jeff DePolo wrote: Real world transmitters always have limiters. Those DO change flatness. That keeps throwing me. I hear 'limiter' and I go towards the receiver. A limiter is a low IF amplifier that is biased to go into saturation with very little input. This clips off amplitude peaks, on even weak signals, which are going to be generated by either man-made or natural noise. Thus the advantage of using FM in the first place. I'm used to calling what you describe a 'clipper' or, in Motorola terminology, an IDC circuit. Ah well, you say 'tomato' and I say 'rutabaga'...;cD -- Jim Barbour WD8CHL
Re: [Repeater-Builder] Re: fixed-audio?
Hi Mike, I'd like to see a controller that has enough in it that all you need to interface to is discriminator audio and modulator audio. On the receive side it could have a Micor-type squelch and a de-emphasis network built with 1% parts. On the transmit side it has pre-emphasis and feeds the modulator directly. So that's one vote for running pre-emphasized audio throughout the controller. To do that, all receivers must provide discriminator audio, and the controller's internal tone generation and digital audio playback must have pre-emphasis. The DTMF decoders must have de-emphasis. Any autopatch would need de-emphasis on the outgoing audio and pre-emphasis on the incoming audio. Am I missing anything? 73, Bob AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com. =0
RE: [Repeater-Builder] ICM Crystals Off Frequency?
At 3/14/2007 22:04, you wrote: Robin, I'm guessing that you ordered bare crystals to put into channel elements that had been previously compensated for other crystals. It's not surprising that they did not operate properly. Wait a minute - he said the new xtals were 36 kHz off frequency @ 147.105 MHz. That's a long ways off, more than you would normally be able to warp them with capacitance. I'm going to go out on a limb here say this has nothing to do with having the elements matched. FWIW, I've rerocked dozens of GE xtal modules ICOMs over the years never had a problem getting the xtals on frequency. Temperature stability is another issue; I take a different approach by removing all compensation in the module temperature-stabilizing the xtal itself. Bob NO6B
Re: [Repeater-Builder] Re: fixed-audio?
Hi NJ, ... The solution seems to be to run flat audio within the controller, ... I couldn't agree more. Coming from the commercial two-way world, this is how we do everything, but I do understand why some repeater builders want to go the other way. I just wouldn't call it flat audio - it's just normal audio - hook a transmission test set up to it and it sounds normal. Okay, that's a vote for running, um, normal audio throughout the controller. To do that, we would accept normal audio from receivers as-is, or de-emphasize discriminator audio. The controller's internal tone generation and digital audio playback, the DTMF decoders, and the autopatch all stay normal. We wouldn't need squelch circuits and we wouldn't need pre-emphasis and clippers in the transmitter audio. It would definitely be less expensive. And normal. :-) 73, Bob AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com.
[Repeater-Builder] Re: ICM Crystals Off Frequency? (More MSR-2000 stories)
Hi Robin, There is a range adjustment under the cover of In/on some msr-2000 mitrek channels. You simply need to range the coarse adjustment within the ball park. Also know the crystals will age and change a bit over the first few months of operation. Some people cut open the channel element top to expose the coarse range adjustment but I've never bothered. Just know the channel element cover being on or off will change the output Frequency quite a bit. So you need to ensure the alignment is checked with the cover in place. Funny... I had this same problem the last time I bought ICM rocks. But I don't have this problem when using Bomar crystals. Both brands of crystals work very well... I just like Bomar's much cheaper price. cheers, skipp Robin Midgett [EMAIL PROTECTED] wrote: Either I'm missing something or ICM sent me defective crystals. I ordered two pairs of crystals to put a MSR-2000 repeater on 147.105 Tx / 147.705 Rx. I've tried both Tx crystals in the KXN1095A channel element only to find the frequency to end up ~36kHz. high. The crystal itself is putting out energy at 12.26180 MHz.; it should be 12.25875 MHz. The bag label indicates them to be cut for 12.25875, but they don't oscillate at (barely even near) that frequency. Should I have to pad the new crystals with a cap to net them on frequency? If so, what value? Thanks, Robin Midgett K4IDC VHF+ Glutton EM66se
[Repeater-Builder] Re: fixed-audio?
Jim B. [EMAIL PROTECTED] wrote: Jeff DePolo wrote: Real world transmitters always have limiters. Those DO change flatness. That keeps throwing me. I hear 'limiter' and I go towards the receiver. A limiter is a low IF amplifier that is biased to go into saturation with very little input. It's one application for a limiter... you can also have a limiter in the audio stage and at the front end of a transmitter in the modulator section (typical). This clips off amplitude peaks, on even weak signals, which are going to be generated by either man-made or natural noise. Thus the advantage of using FM in the first place. Don't make the mistake of using clip for every limiter ap you run into. It's a description. In the case of an IF Limiter it's probably just fine. In the case of an audio limiter you don't have to clip the signal. I'm used to calling what you describe a 'clipper' or, in Motorola terminology, an IDC circuit. Ah well, you say 'tomato' and I say 'rutabaga'...;cD -- Jim Barbour WD8CHL Depending on how the circuit is designed... a tx limiter can be set up to hard compress, which some people interchange as a limiter function. You'll probably find most compress type limiters also follow up with a hard fixed limiter of some type. cheers, s.
RE: [Repeater-Builder] Re: fixed-audio?
Real world transmitters always have limiters. Those DO change flatness. That keeps throwing me. I hear 'limiter' and I go towards the receiver. Actually, it wasn't me that said Real world transmitters always have limiters. I know it was just a cut n' paste mistake, no offense taken. But I wouldn't have said that, because many real world transmitters don't have limiters. --- Jeff
Re: [Repeater-Builder] Re: fixed-audio?
Hi Jeff,
Bottom line: limiting after preemphasis results in a reduction in the
noise-limited dynamic range at higher frequencies; that's a natural
byproduct of a process which originated in the user's radio. The
repeater,
following the same preemphasis/deemphasis curve as the user's radio,
has no
further affect. Any variation or degradation in frequency response,
S/N,
THD, etc. as the audio passes through the repeater is solely due to
imperfections in the design, implementation, or medium, not the
preemphasis/deemphasis process within the repeater since the two are
receiprocol.
How true.
Beyond that, our long-held view here is that the major bad guy
(especially in linked systems, where there is a series of them) is the
post-clipper ('splatter') filter. If they're all first-order filters,
you'll lose 6 dB at the high end (3 kHz) for each one you go through.
No wonder some systems sound muddy.
And no wonder the no-emphasis repeater builders have had success with
their technique.
When you take discriminator audio, run it through your own clipper and
brick-wall filter, and feed it into the modulator, you bypass a lot of
original audio circuitry. The explanation seems to be, de-emphasis and
pre-emphasis is bad because when I got rid of it, my system sounded
better. But it wasn't the de-emph and pre-emph, it was the OEM clipper
and filter.
You can make a good argument for replacing OEM audio circuitry,
including the squelch. But doing it for each port on a multiport
controller is probably too expensive for most of the market.
73,
Bob
AOL now offers free email to everyone. Find out more about what's free
from AOL at AOL.com.
[Repeater-Builder] Re: Flat Audio
But an over deviated new radio doesn't sound crappy in the typical operators hands. It often sounds pretty darn good/loud. So the mfgrs keep sending them out hot and few people complain about it. And repeaters which 'fix' the problem for them doesn't help, either. By the nature of the beast.. most all standard repeater operation should clean up a wide input signal through the repeat process. It may not be optimal but it's realistic. Pretty much everyone is doing it. Then there is the adjacent channel interference they create. There is nothing you can say that will convince me that any repeater can solve that problem. Wide doesn't always equal an interference problem. In most cases a hot radio is perceived to sound good. Sure there's a way to solve the wide deviation problem. Information and education is a real good start. We have to be realistic Joe. But you have some solution for the problem of over deviated radios that doesn't torque off the user? I don't care about them being torqued off. They just should be aiming it in the right direction - at the manufacturer who misaligned their radio. In reality... the radio is misaligned in your opinion. Many others might also have the same opinion... myself included but it's the mfgrs opinion on how the radio best operates out of the box and it's very legal. A good ham should want their radio to be in proper working order. If they get mad, let them have one that sounds bad. But, don't try to compensate for those who don't care what they sounds like. They won't appreciate it anyway. Again... most over deviated radios don't sound that bad. In fact most of them sound pretty good. But they are still over deviated buy the standards used for traditional and current fm repeater operation in the 2 meter band. Again this is the problem in today's ham radio - people are so worried about hurting the feelings of others they won't even tell them when they need their radio fixed. We have not experienced or heard about this being a major problem. In the few times really hot radios have come on the system we describe the deviation problem and try to help the user resolve it. We don't tell them the radio needs to be fixed. Only that the radios out of the box alignment is not optimal for standard voice repeater operation and what options they may have to resolve those issues. That's why some people feel it necessary to compensate for them rather than be honest with them. Same reason we have an industry of small blue pills. In the real world... most users never really experience popping in and out of he receiver for a number of reasons. When visitors to our machines pop in and out of the receiver... we tell them to turn the mic sideways and talk across it. We also explain why and a few of them actually get their radio serviced or remember to talk across the mic when they pop in and out of repeater receivers. And that is much closer solving the problem, not the symptom. It has the effect of lowering the user deviation through proper usage techniques. Silly guy... we know that... that's why we ask them to try it. Much of the time it works just peachy. Now, if they would only really limit the deviation rather than doing it through operating procedures, that would be ideal. But, again, too many hams are appliance operators only. .! sorry. I feel asleep again. Of course, nearly everyone with experience knows that in time of emergency, nearly all compensation techniques will go out the door and the person will be right back up on the mic. Once again... try the decafe Joe. Criticizing others personally is a sign of poor character. Criticize my comments, debate them, or accept them. Don't try to avoid them like this. I care not to debate you Joe... just to make sure your blood pressure is in check and that you stop listening to so much Michael Savage on the broadcast radio. Squelch crash? What does that have to do with audio processing? That is a function of an audio delay circuit (a proper one which will not change the audio at all, but simply mutes it); Wow Joe... you're running on heavy fuel again. Anyway... we don't need audio delays to prevent squelch crash noise. Please let us know what audio delay line you've found that doesn't change the audio at all. I've not seen that circuit yet. There are lots of them that don't intentionally change the audio. Many of the newer digital units do a much better job of it. I'm still waiting to read which audio delay you report, which will not change the audio at all? I've heard a lot of repeaters with audio delays that have excellent audio. zz Which units do you know of that intentionally change the audio in some way? Nice try at a question turn around... how about you answer my original question first. Tag, you're it now. What do you do to
Re: [Repeater-Builder] Re: fixed-audio?
'nj902' wrote: Real world transmitters always have limiters. Those DO change flatness. That keeps throwing me. I hear 'limiter' and I go towards the receiver. Jeff DePolo wrote: Actually, it wasn't me that said Real world transmitters always have limiters. I know it was just a cut n' paste mistake, no offense taken. But I wouldn't have said that, because many real world transmitters don't have limiters. --- Jeff You're absolutely right-sorry about that, Jeff, I missed the original post. It was 'nj902' wb0emu that posted the comment. Now corrected =c) -- Jim Barbour WD8CHL
[Repeater-Builder] Sinclair Q202GR and Q2220E
Hi, I need advise and recommendation from any of you repeater guru's here and help me to choose between this two filter. Sinclair Q202GR or Q2220E? Thanks Azam
[Repeater-Builder] help?marconi rc690.
hi can any one help pls i have 6 marconi rc690s vhf.all on 2m. thay all trainsmit on the corrcet freqs and recive,but the audio sounds like muffled,like in the back of the box. u can just make out what people r saying .any one ever converted one b4?from what i know, this is all u need to do is to change 1 epprom, witch was done on 2m. i was told no ajustment was req? any help pls i am stuck i have been doing this for over a year,this is all i need to get them all working.thanks vince 73s
RE: [Repeater-Builder] ICM Crystals Off Frequency?
Thanks Bob...glad to see someone else on this list has done what I've done in the past. I too have had no problems putting crystals in elements and having them work properly. The repeater environment is stable; it's co-located with a UHF TV transmitter, and the owner pays close attention to such. I'm NOT trying to cut corners guys, just trying to do what I've had success with in the past. At 09:51 AM 3/15/2007, you wrote: At 3/14/2007 22:04, you wrote: Robin, I'm guessing that you ordered bare crystals to put into channel elements that had been previously compensated for other crystals. It's not surprising that they did not operate properly. Wait a minute - he said the new xtals were 36 kHz off frequency @ 147.105 MHz. That's a long ways off, more than you would normally be able to warp them with capacitance. I'm going to go out on a limb here say this has nothing to do with having the elements matched. FWIW, I've rerocked dozens of GE xtal modules ICOMs over the years never had a problem getting the xtals on frequency. Temperature stability is another issue; I take a different approach by removing all compensation in the module temperature-stabilizing the xtal itself. Bob NO6B Yahoo! Groups Links Thanks, Robin Midgett K4IDC 615-322-5836 office - rolls to pager 615-835-7699 pager 615-301-1642 home [EMAIL PROTECTED] http://www.people.vanderbilt.edu/~robin.midgett/index.htm
Re: [Repeater-Builder] Re: ICM Crystals Off Frequency? (More MSR-2000 stories)
Hi Skipp, I've looked and not found such an adjustment. The RBTI page shows a hidden variable inductor, but that isn't the element I have. The element I have is labeled KXN1095A; maybe that's not what I have, but that's the label on it. This element has the IDC adjustment, and one variable inductor for frequency adjustment. There's an access hole in the top of the element cover for each. At 10:01 AM 3/15/2007, you wrote: Hi Robin, There is a range adjustment under the cover of In/on some msr-2000 mitrek channels. You simply need to range the coarse adjustment within the ball park. Also know the crystals will age and change a bit over the first few months of operation. Some people cut open the channel element top to expose the coarse range adjustment but I've never bothered. Just know the channel element cover being on or off will change the output Frequency quite a bit. So you need to ensure the alignment is checked with the cover in place. Funny... I had this same problem the last time I bought ICM rocks. But I don't have this problem when using Bomar crystals. Both brands of crystals work very well... I just like Bomar's much cheaper price. cheers, skipp Robin Midgett [EMAIL PROTECTED] wrote: Either I'm missing something or ICM sent me defective crystals. I ordered two pairs of crystals to put a MSR-2000 repeater on 147.105 Tx / 147.705 Rx. I've tried both Tx crystals in the KXN1095A channel element only to find the frequency to end up ~36kHz. high. The crystal itself is putting out energy at 12.26180 MHz.; it should be 12.25875 MHz. The bag label indicates them to be cut for 12.25875, but they don't oscillate at (barely even near) that frequency. Should I have to pad the new crystals with a cap to net them on frequency? If so, what value? Thanks, Robin Midgett K4IDC VHF+ Glutton EM66se Yahoo! Groups Links Thanks, Robin Midgett K4IDC 615-322-5836 office - rolls to pager 615-835-7699 pager 615-301-1642 home [EMAIL PROTECTED] http://www.people.vanderbilt.edu/~robin.midgett/index.htm
[Repeater-Builder] Re: ICM Crystals Off Frequency?
Wait a minute - he said the new xtals were 36 kHz off frequency @ 147.105 MHz. That's a long ways off, more than you would normally be able to warp them with capacitance. Yes it is a long way off the desired xtal frequency... The hidden channel element coarse frequency adjustment would probably cover the range in some cases. It is not a variable capacitor... but a slug tuned inductor. cheers, s.
Re: [Repeater-Builder] Re: fixed-audio?
At 3/14/2007 05:27 PM, you wrote: On 3/14/07, nj902 [EMAIL PROTECTED] wrote: Another post suggested checking the frequency response of your repeater. Definitely - do that. Try it a various deviations. You may be surprised at how ugly it gets. Sure would be nice to see ARRL labs do a shootout of repeater controllers with tests like this one... they spend days and days (and page after page) testing out $10,000 HF rigs... My experience has been that the controller has little to do with overall repeater audio quaility, what few deficiencies I've found in them (mainly the input coupling deemphasis capacitors in LinkComm controllers being too low in value) are easily corrected. What's most important is how the controller is coupled to the radios that the levels are properly adjusted. Bob NO6B
Re: [Repeater-Builder] Re: Flat Audio
Then there's DTMF.. DTMF decoders HATE the high tone being louder than the low tone. With pre-emphasized audio and a flat receiver, that's what you'll get. In the telco world, this is called reverse twist. Typical DTMF chips work over a 30dB range in amplitude. If your DTMF decode shows any sensitivity to the level adjustment, you have reverse twist. To fix that, de-emphasize before feeding the audio to the DTMF chip.
Re: [Repeater-Builder] Re: Flat Audio
skipp025 wrote: But an over deviated new radio doesn't sound crappy in the typical operators hands. It often sounds pretty darn good/loud. So the mfgrs keep sending them out hot and few people complain about it. And repeaters which 'fix' the problem for them doesn't help, either. By the nature of the beast.. most all standard repeater operation should clean up a wide input signal through the repeat process. It may not be optimal but it's realistic. Pretty much everyone is doing it. I give up. This is supposed to be about audio - not deviation. I guess no argument can be made about the audio, so the subject is changed. Again this is the problem in today's ham radio - people are so worried about hurting the feelings of others they won't even tell them when they need their radio fixed. We have not experienced or heard about this being a major problem. In the few times really hot radios have come on the system we describe the deviation problem and try to help the user resolve it. We don't tell them the radio needs to be fixed. Only that the radios out of the box alignment is not optimal for standard voice repeater operation and what options they may have to resolve those issues. Yet you're the one who brought up the users being torqued off. If it isn't a problem, why was it brought up as a concern? Criticizing others personally is a sign of poor character. Criticize my comments, debate them, or accept them. Don't try to avoid them like this. I care not to debate you Joe... just to make sure your blood pressure is in check and that you stop listening to so much Michael Savage on the broadcast radio. Whoever that is. Fine don't debate the issues. Why post a reply? What do you do to eliminate the squelch crash? I have yet to hear anything other than audio delays that will do it with the single exception of the Micor which will have a very short crash (almost to the point of a click) on strong signals. But, it is still there, and weak signals still have the traditional crash. Joe M. Sure... I'll tell you the msr-2000 repeater has a dual squelch circuit in normal repeater operation. Proper adjustment of both squelch levels pretty much removes any crash noise. No audio delay lines and everyone sounds like a breath of spring... It gives everyone an Irish accent? ;- Joe M.
Re: [Repeater-Builder] ICM Crystals Off Frequency?
Why yes, John, I believe there is. - Original Message - From: WD7F - John in Tucson [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Thursday, March 15, 2007 7:08 AM Subject: Re: [Repeater-Builder] ICM Crystals Off Frequency? Doesn't the MSR-2000 use the crystal element that has an internal range adjustment? Seems to me that when we converted one about four years ago, it wouldn't warp high (maybe it was low) enough. We opened the thing up and found a trimmer in there, moved it slightly and put it back together. We were then able to get it on frequency with the external adjustment. I might have been a tuning slug...I've slept too many times since then so I don't remember. However, I do remember opening the element and tweaking it. de WD7F John in Tucson - Original Message - From: Robin Midgett [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, March 14, 2007 10:02 PM Subject: [Repeater-Builder] ICM Crystals Off Frequency? Either I'm missing something or ICM sent me defective crystals. I ordered two pairs of crystals to put a MSR-2000 repeater on 147.105 Tx / 147.705 Rx. I've tried both Tx crystals in the KXN1095A channel element only to find the frequency to end up ~36kHz. high. The crystal itself is putting out energy at 12.26180 MHz.; it should be 12.25875 MHz. The bag label indicates them to be cut for 12.25875, but they don't oscillate at (barely even near) that frequency. Should I have to pad the new crystals with a cap to net them on frequency? If so, what value? Thanks, Robin Midgett K4IDC VHF+ Glutton EM66se Yahoo! Groups Links -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.446 / Virus Database: 268.18.11/721 - Release Date: 3/13/2007 4:51 PM Yahoo! Groups Links -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.446 / Virus Database: 268.18.11/721 - Release Date: 3/13/2007 4:51 PM
Re: [Repeater-Builder] Re: Flat Audio
At 3/15/2007 09:48 AM, you wrote: Then there is the adjacent channel interference they create. There is nothing you can say that will convince me that any repeater can solve that problem. Wide doesn't always equal an interference problem. ..if your channel spacing is 20 or 25 kHz. At 12.5 or 15 kHz spacing, an overdeviated signal is going to put a significant amount of energy into the adjacent channels, if there's something there, interference is very likely. It's true that it's quite difficult to get all the users' radios down to less than 5 kHz deviation, so deviation limiting post-limiter low pass filtering is important on repeaters operating on narrow spaced channels. On 2 meters in SoCal the standard is 4.2 kHz peak deviation 20 dB down @ 4.4 kHz modulating frequency. Yes it hurts the audio fidelity a bit but ya gotta give up something when you go below 20 kHz channel spacing. Bob NO6B
Re: [Repeater-Builder] Re: ICM Crystals Off Frequency? (More MSR-2000 stories)
When you ordered the crystals, did you specify that they were for a 1095A element? If ICM assumed that they were for a 1088B (.0005%), that might account for the difference maybe... maybe not ? George, KA3HSW / WQGJ413 -Original Message- From: Robin Midgett [EMAIL PROTECTED] Sent: Mar 15, 2007 2:43 PM To: Repeater-Builder@yahoogroups.com Cc: [EMAIL PROTECTED] Subject: Re: [Repeater-Builder] Re: ICM Crystals Off Frequency? (More MSR-2000 stories) Hi Skipp, I've looked and not found such an adjustment. The RBTI page shows a hidden variable inductor, but that isn't the element I have. The element I have is labeled KXN1095A; maybe that's not what I have, but that's the label on it. This element has the IDC adjustment, and one variable inductor for frequency adjustment. There's an access hole in the top of the element cover for each.
Re: [Repeater-Builder] Re: Flat Audio
Yes, you should de-emph the audio going to a DTMF deocder and autopatch, and pre-emph the audio coming from the autopatch is using a flat audio response system. Joe M. david vanhorn wrote: Then there's DTMF.. DTMF decoders HATE the high tone being louder than the low tone. With pre-emphasized audio and a flat receiver, that's what you'll get. In the telco world, this is called reverse twist. Typical DTMF chips work over a 30dB range in amplitude. If your DTMF decode shows any sensitivity to the level adjustment, you have reverse twist. To fix that, de-emphasize before feeding the audio to the DTMF chip.
Re: [Repeater-Builder] Re: ICM Crystals Off Frequency? (More MSR-2000 stories)
Bingo! Thanks George. That is exactly what happened. Apparently if I can find a set (actually a pair; main back up) of the 5PPM elements I will be in good shape. At 01:43 PM 3/15/2007, you wrote: When you ordered the crystals, did you specify that they were for a 1095A element? If ICM assumed that they were for a 1088B (.0005%), that might account for the difference maybe... maybe not ? George, KA3HSW / WQGJ413 -Original Message- From: Robin Midgett [EMAIL PROTECTED] Sent: Mar 15, 2007 2:43 PM To: Repeater-Builder@yahoogroups.com Cc: [EMAIL PROTECTED] Subject: Re: [Repeater-Builder] Re: ICM Crystals Off Frequency? (More MSR-2000 stories) Hi Skipp, I've looked and not found such an adjustment. The RBTI page shows a hidden variable inductor, but that isn't the element I have. The element I have is labeled KXN1095A; maybe that's not what I have, but that's the label on it. This element has the IDC adjustment, and one variable inductor for frequency adjustment. There's an access hole in the top of the element cover for each. Yahoo! Groups Links Thanks, Robin Midgett K4IDC 615-322-5836 office - rolls to pager 615-835-7699 pager 615-301-1642 home [EMAIL PROTECTED] http://www.people.vanderbilt.edu/~robin.midgett/index.htm
Re: [Repeater-Builder] Re: Flat Audio
At 3/15/2007 12:48 PM, you wrote: Yes, you should de-emph the audio going to a DTMF deocder and autopatch, and pre-emph the audio coming from the autopatch is using a flat audio response system. ...hence the source of all the confusion: to build a flat audio response system you need to put de-emphasis on this that pre-emphasis that the other so as to shape the flat audio coming in going out so that it's actually pre-emphasized. -( ) Bob NO6B
[Repeater-Builder] Icom repeater parts?
Hi Guys: A couple weeks ago, I asked whether anyone had a spare internal harness for an IC-RP4020 UHF repeater. I found a VHF unit and used it as parts. After all the work of changing the wires around, I find that the repeater has an output of only 3 watts. I snapped the brick apart and found that the final transistor was shot (great input, no output). So now, I'm in dire needs of: a) a good working SC- brick (same as a M67703M) or b) an entire PA assembly I have a complete IC-RP1520 repeater to use as a bartering tool, minus the harness and the RX section :) Failing that, I guess the club will have to fork over the $US125 from RF Parts. Tedd Doda, VE3TJD Lazer Audio and Electronics Baden, Ontario, Canada www.ve3tjd.com (personal) www.eraradio.ca (Linked repeater system)
Re: [Repeater-Builder] Sinclair Q202GR and Q2220E
At 12:06 AM 3/15/2007, you wrote: Hi, I need advise and recommendation from any of you repeater guru's here and help me to choose between this two filter. Sinclair Q202GR or Q2220E? ---When in doubt, always go for the bigger cans. Then again, you haven't said what kind of power you're planning on running through 'em - that makes a big difference in how much isolation you need. Ken (a user of a Q201G 6 cavity duplexer on VHf and couldn't be happier with 110 watts into it) -- President and CTO - Arcom Communications Makers of the world famous RC210 Repeater Controller and accessories. http://www.arcomcontrollers.com/ Coming soon - the most advanced repeater controller EVER. Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net
Re: [Repeater-Builder] Re: fixed-audio?
[EMAIL PROTECTED] wrote: So that's one vote for running pre-emphasized audio throughout the controller. To do that, all receivers must provide discriminator audio, and the controller's internal tone generation and digital audio playback must have pre-emphasis. The DTMF decoders must have de-emphasis. Any autopatch would need de-emphasis on the outgoing audio and pre-emphasis on the incoming audio. Am I missing anything? Yes, internal transmitter processing. Consider the AP-50, please. It is 'programmable' as to what type of audio feeds the processor, and what type of audio feeds the transmitter, using jumpers. Since there is nothing inherently evil about de or pre emphasis, why MUST we build a controller that has to deal with pre-emphasized audio? I think we simply need to ensure that our controllers audio path is good from 50 to 5000 cycles (most aren't and that's where the problem lies). Design the receiver de-emphasis so the knee is at 50 cycles (YES 50 Hz, you listening CAT ?) Then, ensure the upper edge of the audio spectrum is at at least 5000 Hz. With modern high slew rate op-amps, this isn't hard to accomplish, just don't use a LM-1458. Depending on the builder, possibly the greatest advantage flat audio modification provides is usually a better modulator for the transmitter, and greater conveyed audio bandwidth. In most cases people building flat audio repeaters will convert the pm exciter to true FM and will ensure the audio reaching the transmitter hasn't been high pass filtered to death (somebody say TS-32 HPF) and, isn't low pass filtered to death (they aren't using the original clipper/filter blob in the exciter that may have a high cut off of 2K or slightly more). It's the cascading effects of the filtering that makes links sound bad, not the emphasis stages. Kevin Custer
Re: [Repeater-Builder] Re: fixed-audio?
At 08:39 AM 03/15/07, you wrote: Hi Mike, I'd like to see a controller that has enough in it that all you need to interface to is discriminator audio and modulator audio. On the receive side it could have a Micor-type squelch and a de-emphasis network built with 1% parts. On the transmit side it has pre-emphasis and feeds the modulator directly. So that's one vote for running pre-emphasized audio throughout the controller. To do that, all receivers must provide discriminator audio, and the controller's internal tone generation and digital audio playback must have pre-emphasis. The DTMF decoders must have de-emphasis. Any autopatch would need de-emphasis on the outgoing audio and pre-emphasis on the incoming audio. Am I missing anything? 73, Bob Replied off-list. Mike
[Repeater-Builder] Re: Sinclair Q202GR and Q2220E
If you need the compact footprint go for the Q2220E. If size is not an issue, I highly recommend the Q202 or Q201, especially for high power operation. Another good option, especially for a 600Khz split, is a Q2330E, 6 cavity. Stay away from the compact duplexers sinclair makes. I use two older style Q202 duplexers in VHF service at about 75 watts. Very low loss, and good isolation. Additional bandpass cavities always provide more isolation (A Q201 is a Q202 with a single bandpass cavity on each of the TX and RX legs). They are also very simple to tune. To be honest, I butchered my Q2220E after poor performance at 75 watts / 600 khz and turned it into a very good 220Mhz duplexer. http://www.irlp.net/duplexer/ Dave Cameron VE7LTD --- In Repeater-Builder@yahoogroups.com, Azam [EMAIL PROTECTED] wrote: Hi, I need advise and recommendation from any of you repeater guru's here and help me to choose between this two filter. Sinclair Q202GR or Q2220E? Thanks Azam
Re: [Repeater-Builder] Re: Sinclair Q202GR and Q2220E
At 04:06 PM 3/15/2007, you wrote: (A Q201 is a Q202 with a single bandpass cavity on each of the TX and RX legs). My Q201G has 3 Bp/Br cavities in each leg, not simply extra bandpass cavities. Ken -- President and CTO - Arcom Communications Makers of the world famous RC210 Repeater Controller and accessories. http://www.arcomcontrollers.com/ Coming soon - the most advanced repeater controller EVER. Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net
RE: [SPAM] [Repeater-Builder] Flat Audio
Shorty, I use GE Mastr II repeaters Mastr II mobiles for links. All these flat audio modifications are a waste of time. We have over 4 hops of links. The difference in simplex duplex audio, if any, ain't enough to worry about. I don't understand the need to carve on perfectly good radios, designed by engineers a whole lot smarter than I, gain very little in the real world. Time money can be put to better use on the real important stuff like antennas, duplexers, feed line, controller, a good repeater to start with. I think sometimes modifications are done just for the sake of modifications. Fred N4GER -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Shorty Stouffer Sent: Wednesday, March 14, 2007 2:19 PM To: repeater builder Subject: [SPAM] [Repeater-Builder] Flat Audio Hi Group, Some comments of the flat audio thread... Flat Audio through a repeater simply means that the repeater does not mess with the audio through-put. The End-to-End audio path is flat through the repeater. There is no de-emphasis or pre-emphasis going on inside the repeater audio path. The repeater receiver leaves the audio alone, the controller leaves it alone, and the repeater transmitter leaves it alone. One of the tests that should be performed on every repeater is to test the audio frequency response through the repeater. A signal generator should be connected to the repeater receiver, and a full-quieting 1 kHz tone should be sent into the receiver, at say 3 kHz deviation. The repeater transmitter should be adjusted to also be transmitting 3 kHz of deviation, as measured on a service monitor. Then the audio frequency should be swept between 300 Hz and 3000 Hz in 100 Hz steps on the signal generator, and the transmitter deviation should not vary more than 1% or 2% from the 3 kHz deviation as viewed on the service monitor. That is flat audio through a repeater. In practical real-world service, every users transmitter pre-emphasizes the audio on transmit, and every users radio de-emphasizes the audio on receive. The repeater should leave the through-put audio alone, and your repeater will sound just like simplex does. No audio processing should be done inside the repeater, period. Jeff (Shorty) Stouffer, K6JSI Home: 760/ 724-4020 Cell: 760/ 716-7033 The WIN System The American Red Cross winsystem.org flataudio.com _ Western Intertie Network www.winsystem.org
[Repeater-Builder] RF Sampler
I have a Nice Coaxial Dynamics Wattmeter Like the bird and it uses the same elements but nice Big Display for us older People. Anyway it is Made very Well and not much RF gets out , So the question is How can I make Something get a sample Of RF enough for the Freq Counter to read . I was thinking about drilling a hole and putting a BNC connecter on it and inside just some type of small loop of wire. Anyone who has done something like this and has any Ideas it would be greatly appreciated, Just think the old heath Kit Cantenna Oil Dummy Load had a RCA port on top and that was 50 Yrs ago I think that was used for a Scope. To check the AM Signal. The Measurements will mostly on VHF-UHF All the Way to 927 Mhz Thanks Don KA9QJG
Re: [Repeater-Builder] help?marconi rc690.
Marconi RC690 is a 25w AM radio. Perhaps thats why your rx audio is so bad,its slope detecting the FM. You could use the radios just talking to each other on an AM only net... Ian G8PWE UK - Original Message - From: vince To: Repeater-Builder@yahoogroups.com Sent: Thursday, March 15, 2007 5:46 PM Subject: [Repeater-Builder] help?marconi rc690. hi can any one help pls i have 6 marconi rc690s vhf.all on 2m. thay all trainsmit on the corrcet freqs and recive,but the audio sounds like muffled,like in the back of the box. u can just make out what people r saying .any one ever converted one b4?from what i know, this is all u need to do is to change 1 epprom, witch was done on 2m. i was told no ajustment was req? any help pls i am stuck i have been doing this for over a year,this is all i need to get them all working.thanks vince 73s
[Repeater-Builder] Mastr III
Does anyone have a UHF Mastr III manual that you can sell to me? Fred N4GER
RE: [Repeater-Builder] Mastr III
Fred, There is no one precise thing as a manual. Every radio made by GE was delivered with a combination manual that comprised as many as 12 separate LBI documents collected into one binder. Each of the individual LBIs was selected, based upon the specific modules in the radio. Since each radio might have any one of four or five difference transmitters, exciters, power amplifiers, decoders, receivers, etc., each manual was different. Moreover, the manual you need for your specific radio is based upon each of the modules contained in your radio- and may be unlike any other radio. Please advise exactly what radio you have, by the Combination Number, or by a list of module numbers appearing on each PCB module. The chances are good that the Master LBI Index contains each of the LBIs you need to put together a complete manual that covers your specific radio. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Fred Flowers Sent: Thursday, March 15, 2007 7:00 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Mastr III Does anyone have a UHF Mastr III manual that you can sell to me? Fred N4GER
RE: [Repeater-Builder] Mastr III
Eric, I understand all that. Any of them will have the shelf, the TX RX, system module. Beggars can't be choosers. I can get started with about anything. Fred -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Eric Lemmon Sent: Thursday, March 15, 2007 9:20 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Mastr III Fred, There is no one precise thing as a manual. Every radio made by GE was delivered with a combination manual that comprised as many as 12 separate LBI documents collected into one binder. Each of the individual LBIs was selected, based upon the specific modules in the radio. Since each radio might have any one of four or five difference transmitters, exciters, power amplifiers, decoders, receivers, etc., each manual was different. Moreover, the manual you need for your specific radio is based upon each of the modules contained in your radio- and may be unlike any other radio. Please advise exactly what radio you have, by the Combination Number, or by a list of module numbers appearing on each PCB module. The chances are good that the Master LBI Index contains each of the LBIs you need to put together a complete manual that covers your specific radio. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Fred Flowers Sent: Thursday, March 15, 2007 7:00 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Mastr III Does anyone have a UHF Mastr III manual that you can sell to me? Fred N4GER Yahoo! Groups Links
Re: [Repeater-Builder] RF Sampler
At 06:05 PM 03/15/07, you wrote: I have a Nice Coaxial Dynamics Wattmeter Like the bird and it uses the same elements but nice Big Display for us older People. Anyway it is Made very Well and not much RF gets out , So the question is How can I make Something get a sample Of RF enough for the Freq Counter to read . I was thinking about drilling a hole and putting a BNC connecter on it and inside just some type of small loop of wire. Anyone who has done something like this and has any Ideas it would be greatly appreciated, Just think the old heath Kit Cantenna Oil Dummy Load had a RCA port on top and that was 50 Yrs ago I think that was used for a Scope. To check the AM Signal. The Measurements will mostly on VHF-UHF All the Way to 927 Mhz Thanks Don KA9QJG Go to www.repeater-builder.com and scroll down to Construction Projects. The first item on that page is just what you are looking for. Mike WA6ILQ
Re: [Repeater-Builder] RF Sampler
At 06:05 PM 03/15/07, you wrote: I have a Nice Coaxial Dynamics Wattmeter Like the bird and it uses the same elements but nice Big Display for us older People. Anyway it is Made very Well and not much RF gets out , So the question is How can I make Something get a sample Of RF enough for the Freq Counter to read . I was thinking about drilling a hole and putting a BNC connecter on it and inside just some type of small loop of wire. Anyone who has done something like this and has any Ideas it would be greatly appreciated, Just think the old heath Kit Cantenna Oil Dummy Load had a RCA port on top and that was 50 Yrs ago I think that was used for a Scope. To check the AM Signal. The Measurements will mostly on VHF-UHF All the Way to 927 Mhz Thanks Don KA9QJG Go to www.repeater-builder.com and scroll down to Construction Projects. The first item on that page is just what you are looking for. Mike WA6ILQ
RE: [Repeater-Builder] RF Sampler
Also Bird makes a element that has a bnc connector. Fred N4GER -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Mike Morris WA6ILQ Sent: Thursday, March 15, 2007 9:33 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] RF Sampler At 06:05 PM 03/15/07, you wrote: I have a Nice Coaxial Dynamics Wattmeter Like the bird and it uses the same elements but nice Big Display for us older People. Anyway it is Made very Well and not much RF gets out , So the question is How can I make Something get a sample Of RF enough for the Freq Counter to read . I was thinking about drilling a hole and putting a BNC connecter on it and inside just some type of small loop of wire. Anyone who has done something like this and has any Ideas it would be greatly appreciated, Just think the old heath Kit Cantenna Oil Dummy Load had a RCA port on top and that was 50 Yrs ago I think that was used for a Scope. To check the AM Signal. The Measurements will mostly on VHF-UHF All the Way to 927 Mhz Thanks Don KA9QJG Go to www.repeater-builder.com and scroll down to Construction Projects. The first item on that page is just what you are looking for. Mike WA6ILQ Yahoo! Groups Links
RE: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio)
Chuck, You are absolutely correct! However, the specific resistor value used for R405 in each MICOR station was deliberately selected to result in the desired deviation level. Thus, the R405 resistor value (nominally 33 kohms) varies from one station to the next. Note 409 on the schematic for the MICOR TLD5320A Exciter states that R404 and R405 are factory selected so that Private Line deviation falls between 500 Hz and 1000 Hz limits. The point I made was that Alinco, among many other manufacturers, simply used a certain value in almost every radio built, rather than a selected value, with the assumption that it would result in enough CTCSS deviation. As I pointed out, that value more often than not resulted in CTCSS deviation that was far above the appropriate or necessary level. However, as Bob points out, a very few Alinco models have CTCSS deviation adjustment pots, but those are the exception. Without exception, every Alinco radio I have tested- portable or mobile- has had CTCSS deviation above 1000 Hz. That is far too high, and it usually results in talk-off due to tone distortion. As others have noted, this issue of over-deviation of CTCSS tones is definitely not limited to Alinco, but is common practice in Amateur-grade radios. Lest others doubt the accuracy of my measurements, I should state that both of my service monitors have annual calibrations performed by the original vendors, with certifications traceable to the NIST. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Kelsey Sent: Thursday, March 15, 2007 3:45 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio) Commercial radios also used fixed values. The Micor is one example of fixed values for tone deviation. Chuck WB2EDV - Original Message - From: Mike Morris WA6ILQ [EMAIL PROTECTED] mailto:wa6ilq%40pacbell.net To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Wednesday, March 14, 2007 11:37 PM Subject: Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio) At 07:23 PM 03/14/07, Eric Lemmon WB6FLY wrote: Nate, Several years ago, I chastised ARRL Labs for failing to report the basic 2-way radio performance parameters of 12dB SINAD sensitivity, voice deviation limit, CTCSS deviation limit, and center frequency accuracy. I did not get a satisfactory answer, but I suspect that there is a reluctance to disparage the performance of name-brand Ham radios. QST survives on the ads. The league doesn't want to risk the revenue. As the wise man said, he who has the gold makes the rules. Nearly every Amateur 2m radio I have tested has CTCSS deviation far in excess of the EIA/TIA recommended level of 750 Hz, and that level is not adjustable in most radios. Pots cost more than fixed resistors and that would reduce the profits.
Re: [Repeater-Builder] Re: Flat Audio
Yes, you have to make all the audio preemphasized (from the autopatch IF USED) to match the user's audio which is preemphasized. I would not phrase it as put de-emphasis on this that pre-emphasis that the other since that also describes processed audio systems. In most current configurations, this involves simply de-emph on the DTMF decoder (simple enough) which is the same thing you would do with the receiver in a processed audio system, so it's actually much easier than in an unprocessed audio system (half the work). Modern ham controllers even have that built in as a jumper option, so it's not as difficult as put de-emphasis on this that pre-emphasis that the other - it's more like install jumpers 1, 2, and 3 in the A position during setup if you have autopatch or install jumper 1 in the A position if you don't have autopatch. Joe M. Bob Dengler wrote: At 3/15/2007 12:48 PM, you wrote: Yes, you should de-emph the audio going to a DTMF deocder and autopatch, and pre-emph the audio coming from the autopatch is using a flat audio response system. ...hence the source of all the confusion: to build a flat audio response system you need to put de-emphasis on this that pre-emphasis that the other so as to shape the flat audio coming in going out so that it's actually pre-emphasized. -( ) Bob NO6B Yahoo! Groups Links
Re: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio)
OK. Let me approach this from another angle. What is the deviation on your system that is not the standard 5.0 kHz or so (running 16K0F3E)? Joe M. James wrote: Yes, thank you Jim .. I did say channel steps not spacing. 2.5 Khz channel step tends to go with 12.5 KHz channel spacing. 7.5 Khz is a form of ultra narrow that I have yet to use for anything. James Jim B. wrote: mch wrote: 2.5 kHz channel spacing? Where is that used? It's not in the commercial USA market. Or did you mean 7.5 kHz? Joe M. FWIW-He said channel steps, not spacing. James wrote: It even does 2.5 KHz channel steps to comply with modern narrow band channel planning
RE: [Repeater-Builder] RF Sampler
Yes, they do, and they are quite happy to charge over $100 for it. In that article Kevin shows you how to do the same thing for under $10. Yes, it's uncalibrated, but a counter doesn't care. And if you really want to get a calibration on your home-brew one, it's not that hard to measure the insertion loss. Mike WA6ILQ At 07:34 PM 03/15/07, you wrote: Also Bird makes a element that has a bnc connector. Fred N4GER -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Mike Morris WA6ILQ Sent: Thursday, March 15, 2007 9:33 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] RF Sampler At 06:05 PM 03/15/07, you wrote: I have a Nice Coaxial Dynamics Wattmeter Like the bird and it uses the same elements but nice Big Display for us older People. Anyway it is Made very Well and not much RF gets out , So the question is How can I make Something get a sample Of RF enough for the Freq Counter to read . I was thinking about drilling a hole and putting a BNC connecter on it and inside just some type of small loop of wire. Anyone who has done something like this and has any Ideas it would be greatly appreciated, Just think the old heath Kit Cantenna Oil Dummy Load had a RCA port on top and that was 50 Yrs ago I think that was used for a Scope. To check the AM Signal. The Measurements will mostly on VHF-UHF All the Way to 927 Mhz Thanks Don KA9QJG Go to www.repeater-builder.com and scroll down to Construction Projects. The first item on that page is just what you are looking for. Mike WA6ILQ Yahoo! Groups Links Yahoo! Groups Links
RE: [Repeater-Builder] RF Sampler
I see them a hamfests for less. -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Mike Morris WA6ILQ Sent: Thursday, March 15, 2007 10:41 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] RF Sampler Yes, they do, and they are quite happy to charge over $100 for it. In that article Kevin shows you how to do the same thing for under $10. Yes, it's uncalibrated, but a counter doesn't care. And if you really want to get a calibration on your home-brew one, it's not that hard to measure the insertion loss. Mike WA6ILQ At 07:34 PM 03/15/07, you wrote: Also Bird makes a element that has a bnc connector. Fred N4GER -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Mike Morris WA6ILQ Sent: Thursday, March 15, 2007 9:33 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] RF Sampler At 06:05 PM 03/15/07, you wrote: I have a Nice Coaxial Dynamics Wattmeter Like the bird and it uses the same elements but nice Big Display for us older People. Anyway it is Made very Well and not much RF gets out , So the question is How can I make Something get a sample Of RF enough for the Freq Counter to read . I was thinking about drilling a hole and putting a BNC connecter on it and inside just some type of small loop of wire. Anyone who has done something like this and has any Ideas it would be greatly appreciated, Just think the old heath Kit Cantenna Oil Dummy Load had a RCA port on top and that was 50 Yrs ago I think that was used for a Scope. To check the AM Signal. The Measurements will mostly on VHF-UHF All the Way to 927 Mhz Thanks Don KA9QJG Go to www.repeater-builder.com and scroll down to Construction Projects. The first item on that page is just what you are looking for. Mike WA6ILQ Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links
RE: [Repeater-Builder] Amateur-Grade Radios (Was: Fixed Audio)
At 3/15/2007 20:13, you wrote: The point I made was that Alinco, among many other manufacturers, simply used a certain value in almost every radio built, rather than a selected value, with the assumption that it would result in enough CTCSS deviation. As I pointed out, that value more often than not resulted in CTCSS deviation that was far above the appropriate or necessary level. However, as Bob points out, a very few Alinco models have CTCSS deviation adjustment pots, but those are the exception. Guess I'm good at picking out the exceptions. Don't recall for sure, but I think the DR-605's CTCSS level is adjustable too. Either way, the one I owned for a year or so before it was stolen didn't have excessive CTCSS deviation. It is unfortunate that the quality of Alinco's products has deteriorated from what was once quite respectable to utter junk. Without exception, every Alinco radio I have tested- portable or mobile- has had CTCSS deviation above 1000 Hz. That is far too high, and it usually results in talk-off due to tone distortion. Actually, excessive CTCSS deviation is a poor yet effective way to mitigate CTCSS talk-off caused by lack of high-pass filtering in the mic amp circuitry, provided that the total deviation doesn't go much over 5 kHz. Bob NO6B
Re: [Repeater-Builder] Re: Flat Audio
At 3/15/2007 20:18, you wrote: Yes, you have to make all the audio preemphasized (from the autopatch IF USED) to match the user's audio which is preemphasized. I would not phrase it as put de-emphasis on this that pre-emphasis that the other since that also describes processed audio systems. In most current configurations, this involves simply de-emph on the DTMF decoder (simple enough) which is the same thing you would do with the receiver in a processed audio system, so it's actually much easier than in an unprocessed audio system (half the work). Modern ham controllers even have that built in as a jumper option, so it's not as difficult as put de-emphasis on this that pre-emphasis that the other - it's more like install jumpers 1, 2, and 3 in the A position during setup if you have autopatch or install jumper 1 in the A position if you don't have autopatch. All my controllers, which are admittedly not very current, only have de-emphasis jumpers on the radio port inputs. They are designed for flat response audio running through the controller. I guess in some ways it just boils down to personal preference. I just find it easier to work with controller audio that matches the original/final audio. As others have pointed out, running 6 dB/octave pre-emphasis through a controller puts additional dynamic range requirements on its audio circuitry. Of course, all this will be moot when we all switch to DSP controllers (see LinkComm's recent announcement regarding a possible debut @ Dayton). Bob NO6B
[Repeater-Builder] Re: RF Sampler
Don, I have been using UHF and N tees with the center conductor on one side of the tee removed as RF sample ports for more than forty years. Also make great way to inject RF into a system for receiver tests with the antenna and other hardware in place. Cheap enough to leave in line for future use. Used to be called isotees. There is usually enough capacitance at the gap between the center pin of the connector on the isolated side and the now L shaped center conductor of the tee to couple a counter or other test equipment effectively. I usually just put a UHF or N to BNC adaptor on the port of the tee that has the center contact removed. Then use BNC's to the test gear. One does need to CLEARLY mark the port with no center with black or red magic marker to designate that it is different so that someone doesn't think it is a regular tee connector. 73, Al, K9SI Don wrote: RF Sampler Posted by: Don [EMAIL PROTECTED] ka9qjg1 Date: Thu Mar 15, 2007 6:07 pm ((PDT)) I have a Nice Coaxial Dynamics Wattmeter Like the bird and it uses the same elements but nice Big Display for us older People. Anyway it is Made very Well and not much RF gets out , So the question is How can I make Something get a sample Of RF enough for the Freq Counter to read . I was thinking about drilling a hole and putting a BNC connecter on it and inside just some type of small loop of wire. Anyone who has done something like this and has any Ideas it would be greatly appreciated, Just think the old heath Kit Cantenna Oil Dummy Load had a RCA port on top and that was 50 Yrs ago I think that was used for a Scope. To check the AM Signal. The Measurements will mostly on VHF-UHF All the Way to 927 Mhz Thanks Don KA9QJG
Re: [Repeater-Builder] RF Sampler
I picked up a new Bird Sampling slug for $25.00 from a CB shop that didn't know what it was. I just got lucky. Paul Metzger K6EH
RE: [Repeater-Builder] RF Sampler
Paul , the only reason You got that from the CB Shop it would ONLY handle 1500 Watts and they could not use it , Ha Ha Thanks Back to Repeater Building Don KA9QJG
Re: [Repeater-Builder] RF Sampler
On 3/15/07, Paul Metzger [EMAIL PROTECTED] wrote: I picked up a new Bird Sampling slug for $25.00 from a CB shop that didn't know what it was. I just got lucky. Paul Metzger K6EH Sometimes it's better to be lucky than good. :-) Nate WY0X
