Home |
Search |
Today's Posts |
#21
![]() |
|||
|
|||
![]()
I'd like (besides the other specifications) some other things (really cool
for european dxers): FM 64-76 extension (for OIRT dx) RDS (really nice to have FM listening) with PI CODE reception 3 IF FM filters frontend (like Satellit 500 or 700 ... cool for FM dxers -) and two kind of FM selectivity (like 280 and 80 khz Murata filters) it could be really cool mp3 recording and two antenna connector one for FM Antenna and SW and another one for MW antenna to disable internal ferrite. internal ferrite could be switch off besides like in Sangean ATS 909 with a stereo minijack) other suggestions made from other dxers are cool too. Leonardo QTH Matelica (MC) - Italy |
#22
![]() |
|||
|
|||
![]()
Re-reading my first post I noticed two silly errors I made: the slew
buttons on FM should offer 100 kHz tuning (not MHz)- and possibly 50 kHz tuning also - and the internal ferrite antenna for MW and LW should be 260 mm minimum length (not 130). An auxiliary external removeable MW/LW antenna, which could plug into a receptical on the top of the radio, and be rotated would be extremely nice; only the antenna would have to be rotated for best MW/LW reception, not the whole radio. By the way, really "tight" (multiple) filters for FM reception would be a plus. One other suggestion: make the radio BIG - more on the order of the Grundig Satellit 800. Smaller radios involve too much compromise in my opinion. There are certainly enough smaller compromised radios on the market already but very few "great" ones. (The Satellit 800 is close, but the improvements suggested here on this post would result, I believe, in one of the all-time great radios.) Sorry about the errors. Senility ... Best, Joe |
#23
![]() |
|||
|
|||
![]()
Joe Analssandrini schrieb:
One other suggestion: make the radio BIG - more on the order of the Grundig Satellit 800. Now that would be fairly huge. Sure sound could be very good, but portability really suffers. I'd even have trouble fitting such a beast on my desk or nightstand. It would, BTW, be advisable to use the largest speaker that fits the case (unlike the '800, which only uses a 10 cm speaker, a joke given the size of the thing). Stephan -- Meine Andere Seite: http://stephan.win31.de/ PC#6: i440BX, 2xP3-500E, 704 MiB, 18+80 GB, R9k AGP 64 MiB, 110W This is a SCSI-inside, Legacy-plus, TCPA-free computer ![]() |
#24
![]() |
|||
|
|||
![]()
Joe Analssandrini schrieb:
Synchronous-selectable sideband reception is a MUST. I forgot this in my original post. Yup, a low-distortion AM detector of some kind is virtually a must. Notoriously distorted diode detection just doesn't cut it for serious listening. (Besides, the Sat 700 already had synch detection.) Should be designed at least as well as that on the Grundig Satellit 800. Quite tricky, given the folks at DEGEN have no experience building synch detectors so far. Full passband tuning would be even better. Sure, but I've never seen that in a portable. Lock must be held as well as on AR7030 model That would be great. It virtually never unlocks (and even if it does, you don't notice much since the receiver is still using the very low-distortion product detector). BTW, if synch audio quality were anything close to that on the AR7030 this would be great. I was amazed by how good AM can sound that way. (It's just that the AR7030 doesn't match my usage pattern very well and usually resides in its box. Seems silly, but maybe I'll be able to put up a decent antenna one day, and then I'd be sorry to have sold the thing. It's unlikely to lose much in value anyway.) and must automatically turn off when tuning and then re-lock when station is selected. That would be the standard way of implementing it, I think. A good notch filter (with at least 50 dB depth) with range of 0.1 - 5 kHz. That sure would be nice, but did any other portable ever have one? At least 3 IF filters (bandwidths) (preferably 4) of 2.2 kHz, 4 kHz, 6 kHz (and possibly 1 kHz for data/CW); I don't know whether that's realistic in a portable. Still, a 2.2/4/6 kHz combo would work well. operation of these filters should be cascaded so that inexpensive ceramic filters will give much better performance than usual. However, you can't cascade indefinitely. Passband ripple will mess up things at some point. The AR7030, BTW, uses a 4-element 12 kHz tail filter along with some 6-element ceramics and a high-quality SSB filter (Murata CFJ). If a good SSB filter is not within the budget, cascading the 6 and 4 kHz filters might also work (which would give a caascade of the 12, 6 and 4 kHz filters overall). The 12 kHz might also be useful for DRM or really indisturbed AM reception. BTW, with good filtering present, low oscillator phase noise is of high importance. That's one of the reasons why the AR7030 achieves such good selectivity. All shape factors should be less than 1:2. Actually that's true even of the 6-element Muratas like the one used in the 7600GR. Dial illumination via LEDs, perhaps color-switchable (Red, Blue, Green). Now that would be nifty. Dial light scheme similar to Grundig Satellit 800. (Always on or always off with AC power, on for 15 seconds with any button push when using battery power, or always off with batteries, as desired by user.) This concept does not seem so uncommon, our Sony ICF-M60SRDS also uses it. Line outputs for external speaker(s) and stereo system. Excellent sound quality is a must. Shouldn't be that much of a problem, decent-quality opamps like 5532s aren't expensive these days, and decent-quality electrolytics aren't that much of a problem either. Independent tone controls (Treble and Bass) should be incorporated. Internal mono speaker of high quality is preferable to mediocre stereo speakers. ACK. At least two external antenna inputs for AM/SW (high and low impedence) as well as an FM antenna input. That seems reasonable. Now the question is, what norm would the FM ant input conform to? IBOC reception (AM & FM) for the US. Canadian DAB. (Possibly European DAB.) Self-contained DRM (or a 12 kHz IF output to connect to a DRM-equipped computer). I'd consider DRM as a world-wide standard to be more important than DAB. Clocks should be RADIO-CONTROLLED Good idea, but by which time signal station? Making this variable requires considerably more efforts. (Typically a narrow-band LC tuned front-end filter is used, which has to be laid out or at least adjusted differently for the various frequencies, e.g. MSF 60 kHz for UK folks, DCF77 77.5 kHz etc.) (and operated independently from radio and powered via 2 AA or AAA batteries). Two times zones should be available, one of which should be UTC. Local time should be adjustable for daylight-savings time (via radio control) if required; UTC should NOT be affected by DST change. One of the clocks (including seconds) should ALWAYS be visible, radio on or off. Very reasonable suggestions. No LEDs (except for dial illumination and possibly button illumination). Properly calibrated digital bar graph S-meter of at least 12 segments. I guess most people would already be happy with a *useful* meter that doesn't read full strength 95% of the time, yet also catches fairly weak signals and has a pretty wide range. A high-quality plastic cabinet or, preferably, a light-weight metal (aluminum or magnesium) cabinet. I don't know whether a metal case would do the sound aspect any good. Plastic is more realistic anyway. ALL internal components to be of TOP-QUALITY (formerly known as MIL-spec). Isn't that asking a bit too much? Excellent sensitivity; a 3 or 4 step attenuator (or adjustable RF-gain control) should be incorporated. A 2-step attenuator would most likely also do. RF gain was more necessary in the old days to get SSB demodulation with fairly lousy detectors right. A switchable AGP time constant/behavior, however, would be a nice touch. All other specifications to be of Drake R8B/AOR AR7030 caliber, especially blocking, ultimate rejection, image rejection, and, most important, dynamic range. I guess the receiver will be priced at around ~500USD/EUR, so not all of this will be possible. Excellent sensitivity (a 3 or 4 step attenuator would be of help). Depending on how sensitive the thing becomes, either a pre-amp for the whip (as done in the Sat 700) or a pre-attenuated ext ant input (we don't want anything to blow on large antennas) seems like the more likely solution. A carrying case (nylon or leather) should be optionally offered; this should be able to carry AC adapter, batteries, and any other options, as well as fully protecting the radio. Seems like a good idea, though this kind of rig will never be as portable as a DE105. (BTW, I sure would like to get my hands on a DE1105. The '105 isn't bad for what it is, but doesn't perform as well as I'd like. And since the '1105 isn't a lot bigger, this seems like the perfect model to upgrade to.) Servicing is important. All service information should be made available on line. That would be great indeed. At the very least there should be some way of obtaining service docs at all. Stephan -- Meine Andere Seite: http://stephan.win31.de/ PC#6: i440BX, 2xP3-500E, 704 MiB, 18+80 GB, R9k AGP 64 MiB, 110W This is a SCSI-inside, Legacy-plus, TCPA-free computer ![]() |
#25
![]() |
|||
|
|||
![]()
Stephan Grossklass wrote:
Quite tricky, given the folks at DEGEN have no experience building synch detectors so far. I think we've reached the point where a good sync' detector is not exactly rocket science anymore. However the problem is designing one that doesn't infringe on someone elses design. That could be a big problem. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#26
![]() |
|||
|
|||
![]() |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
DEGEN DE1108 worldband receiver is now in preliminary design stage, any one has recommends on it? | Shortwave |