Some people here have mentioned the BBC. In Australia we have sort of the equivalent, ABC FM. It has a whole bunch of stations, each dedicated to a fairly defined (however broad) audience. Like - sports, jazz, country, youth radio (? any age?), news, kids, regional, etc.
I often listen to the Classic station. Sometimes all the time. Excellent reception - helped a bit by an FM omni antenna attached to the TV antenna stem. No advertisements, some chat and interviews, but mostly music. Sometimes live performances. The presenters are invariably quite erudite, sometimes musicians, and sometimes classically trained.
My tuner is a Yamaha T-85, which is about 40 years old but I picked it up a few years ago NOS (still in the unopened box) for a few hundred bucks. I haven't seen one since offered for sale in Australia - maybe I blinked. Despite not appearing on that shootout list which, like others, I find a little bit cringeworthy, it is nevertheless quite highly regarded at that site. Whatever that means.
It appears that the T-85 can be quite an incredibly good tuner with a few mods (EJ3):
Yamaha CSL notes - T-85 mods
Copyright ©2001-2023 Tuner Information Center. Permission is hereby granted to quote our text so long as proper credit is given.
Yamaha T-85
(1986, $500/orig $449,
photo,
closeup,
owner's manual,
ad, service manual:
schematic 1,
schematic 2,
front-end schematic,
adjustments,
circuit boards 1,
circuit boards 2,
remote and CSL,
wiring and ICs)
search eBay
The T-85 is a black-faced digital tuner with good sensitivity and, some say, better audio quality than its main competitors as digital "DX machines," the Onkyo T-9090 and T-9090II. The T-85 has the electronic equivalent of 5 gangs and 4 IF bandwidth settings (Super Wide-Wide-Narrow-Super Narrow), and tunes in .1 MHz increments or fine-tunes in .01 MHz (10 kHz) increments. The ability to detune from strong local stations, together with the T-85's excellent overload rejection, leads some urban DXers to prefer it to the Onkyo T-9090 or T-9090II once the T-85's stock ceramic filters are replaced with narrower ones. The problem for DXers, or others who change stations frequently, is that the T-85's "CSL" (Computer Servo Lock) function requires one to hit the fine-tuning button every time a weak station is manually tuned (whether or not you actually want to fine-tune), in order to defeat the CSL's muting of weak signals. This means that it takes two button-pushes, rather than one, to tune a weak signal, except for those frequencies that have been entered as presets. See our panelist Bob's definitive writeup on the operation of the CSL circuit in the series of posts beginning
here, and there's more on the CSL in the string of posts
here.
Our contributor Bill Ammons offers this technical analysis: "The T-85's RF front end/IF converter is on its own PCB. The RF section has two tuning gangs before the 3SK107 FET. The IF converter is a balanced mixer using two 2SK107 FETs. In the Super Wide mode, the IF consists of two tuned 10.7 stages plus two amplitude adjustments and two 280 kHz ceramic filters. The Wide mode adds one additional 10.7 tuned stage, another amplitude adjustment, and one more ceramic filter. The Narrow mode adds one additional 230 kHz filter to the preceding IF. And in the Super Narrow position, a second 230 kHz filter is added for a total of 5 ceramic filters in the Super Narrow IF chain. This unit is easy to service or modify, but the CSL circuit is even more tricky here than in the TX-900 when it comes to grabbing stations 200 kHz apart."
Some complain about the T-85's ergonomics, but our contributor Ryan notes that it is an underrated audiophile tuner: "Yamaha used a true analog multiplier in the multiplex. The technical description of the multiplex is complex, but suffice to say this is one of the very best ways to decode a stereo signal, but because it costs more than using just one simple chip, it wasn't done frequently. Even in stock form, the T-85 is very good, and I suspect that with carefully matched filters and a few component changes almost nothing could touch it. But of course, it is filter and alignment dependent on what you end up with, as with any tuner. Overall, however, Yamaha made very few mistakes with this tuner, and it's certainly one of the best overall designs ever, in my opinion." Our contributor Charles found one or two mistakes: "One thing I don't like about the T-85's 'auto-mode' IF band selection is that it always seems to go to a narrower bandwidth than I would select. Also, once it goes down to a narrower bandwidth (say, if there's some temporary interference), it never bothers to go back up again, so there's an annoying 'downward ratcheting' effect. On my favorite presets, I defeat the auto-bandwidth."
Our contributor Eli says, "Although it has a reputation as a great DX tuner, there are quite a few tuners with greater selectivity than the T-85 [in stock form]. The T-85's alternate channel selectivity is 90 dB, which is decent, but (in my experience) not quite enough to reliably separate stations that are adjacent (200 kHz away) to stronger local stations. It's sufficient in many cases, but not in all cases. Many of the digital Onkyos will beat it, as will the MR 78, MR 80, a couple of Accuphase models, and some of the top Kenwoods. And the Sony HD tuner will make mincemeat out of it for selectivity. The T-85 needs narrower filters installed in order to compete with the best on selectivity. Its stock filters are a mix of 280 kHz and 230 kHz. In comparison, the Onkyo T-9090II has *5* 150 kHz filters in its Super Narrow mode. All that being said, the T-85 is one of my favorite tuners, maybe even my all-around #1, all things considered. But I just don't want people to go out and buy one expecting super selectivity in stock form." Eli also praises the T-85's AM performance on the
AM Tuners page.
Our contributor Mark modded his T-85 and says, "Performance-wise, the T-85 is amazing. I just finished aligning it and I'm getting over 60 dB of separation at 1 kHz in Super Wide (@.05% distortion) and 50 dB in Wide (@.08% distortion). There are actually separate separation adjustments for L-only and R-only modes in both Super Wide and Wide. Plus the T-85 plays my weak-signal stereo test station (in Super Narrow with the 2 180 kHz GDT filters) BETTER than the RSPdx DSP receiver! That is a first. I wish it had a nice, weighted tuning knob."
Our contributor János compares a T-85 to a Kenwood KT-6040 in our writeup for the latter. János wondered whether the T-85 is bass-shy, to which our panelist JohnC responds: "The T-85's bass can be improved with the replacement of C279 and C280 with 10 µF bipolar capacitors, something like a Nichicon Muse ES series. You can even push it up to 22 µF if you feel comfortable with that." JohnC's full mod recipe for the T-85 can be found on our
DIY Mods page
Our contributor Tim comments on the above writeup and compares a modded T-85 to a couple of other top modded tuners on our
Shootouts 2.0 page. Our contributor Ken K. compares a T-85 to an Onkyo T-4711 in our writeup for the latter, and our contributor Bill C. compares a T-85 to a JVC FX-1100BK in our writeup for the JVC. The T-85's 75-ohm coax jack requires a push-on F-connector, such as Radio Shack catalog #2780291. T-85 sale prices on eBay can be highly variable: anything from $150 to $350 is usually possible, with lows of $100 in 6/09 and $101 in 7/11. All-time highs were $430 and $440 for mint ones in 1-3/06. The clear lesson (as with the T-1) is not to overpay: The T-85 is extremely common and if the price of one gets too high, another one will be along shortly.
The T-85 is worthy of some extra space, so here is some additional detailed information from Yamaha:
"The T-85 Natural Sound AM/FM Stereo Tuner incorporates the most advanced Yamaha tuner technology, making it the uncompromising choice for truly discriminating audio enthusiasts. The T-85 combines a number of proven Yamaha technologies and original features with sophisticated innovations that make it a reference standard in terms of sound quality, reception accuracy and operating ease.
CSL Achieves Exceptional Linearity and Low Noise Throughout Entire Band
The new Computer Servo Lock Tuning (CSL) system achieves stunning levels of performance in the T-85. First and foremost, it provides ideal reception performance under virtually any signal conditions. Also, the design of this system ensures that the tuning voltage itself is completely unaffected by noise from the PLL stage, so the signal-to-noise ratio of the local oscillator depends only on the inherent noise characteristics of the parts making up the local oscillator circuitry. These, of course, have been painstakingly selected to ensure an absolute minimum of noise. The overall result is a remarkably high signal-to-noise ratio across the entire 87.5 to 108.0 MHz band (98 dB mono, 90 dB stereo), with unprecedented linearity throughout the same range.
Four Different Tuning Modes
The T-85 offers auto-search and manual tuning in addition to the preset and fine tuning functions. In the Auto Search mode, the tuner scans the band in the specified Up or Down direction until a strong station is found. In the Manual mode, single-step tuning makes it possible to tune to a station's exact frequency for easy tuning of even weak broadcasts.
20-Station Random Access Preset Tuning
Up to 20 different station frequencies can be stored in memory for instant, accurate tuning at the touch of a button. Any combination of AM and FM stations can be programmed. To tune in a preset station, simply touch the appropriate button and the station will be precisely tuned immediately, for real operating ease and convenience. Station frequency indicator cards are supplied, so you can label your presets for faster, easier station selection.
Station Status Memory
When you enter a particular station into the T-85's preset memory, a few more factors than just the station's frequency are memorized. The tuner remembers whether the Auto Stereo or Mono mode was set, whether the Dynamic Auto Blend function was on or off, whether the Direct or Normal RF mode was selected, whether any manual fine tuning was employed, and which of the four possible IF modes was selected. That way, all necessary parameters for optimum station reception are recalled simultaneously with the station's frequency whenever the preset memory is used.
Last Channel Memory
This handy feature eliminates the need to retune your favorite station each time you turn the power on. When power to the T-85 is switched on, the last station tuned in before the power was turned off is automatically re-selected.
12-Segment Signal Quality Meter
This easy-to-read meter provides an accurate reading of overall signal quality, making it easy to achieve the best possible reception with the manual and digital fine tuning functions. This metering system provides a truly meaningful indication of not just signal strength, but actual signal quality, so that the highest display reading shows the optimum blend of signal strength and signal purity. This is especially helpful when tuning manually with the digital fine tuning control, since it gives a visual indication of the desired tuning point in addition to confirmation by ear.
Dynamic Auto Blend Circuit
When signal quality is low, stereo programs tend to lose quality and suffer increased distortion and noise more than monaural programs do. This special circuit compensates for this by automatically blending the left and right channels of a stereo program when signal quality drops below the limit of acceptable sound quality. The result is greatly reduced noise and distortion with enhanced intelligibility on programs that would otherwise be unlistenable. This circuit is 'dynamic,' too, automatically providing the optimum degree of blend for the prevailing signal conditions."
Yamaha CSL notes - T-85 mods:
12/26/21: JohnC's holiday special kicks off with a comprehensive DIY mod for the superb Yamaha T-85.
All decoupling and power supply caps, Panasonic FR, FM, Nichicon HE, or Panasonic FC in that order, as available, unless noted.
Front End Board
C124 - 1200/16
C130 - 22/25
C132 - 47/25
Detector
C253 - 68/25
Composite/MPX
C259/260 - 1500/16
C261/262 - 1200/16
MPX PLL
C329/330 - 68/25
Audio
C279/280 - 10/50 Nichicon MUSE ES bipolar
Power Mute
C343 - 150/25
C344 - 330/25
Power Supply
C362/363 - 1200/35
-12V Rail
C354 - 22/25
C356 - 47/25
C358 - 1500/35
6V Rail
C353 - 22/25
C355 - 100/25
C357 - 4700/35
8V Rail
C350/351 - 22/25
C352 - 100/25
+12V Rail
C348 - 220/16
C349 - 100/16
30V Rail
C346 - 47/50
C347 - 47/63
C359 - 47/63
Replacement DIP-8 Op-Amp Orientation
IC 203 - Pin 8 into board hole 1
IC 204 - Pin 8 into board hole 9
IC 205 - Pin 8 into board hole 9
IC 210 - Pin 8 into board hole 9 with a jumper between board holes 1 and 9
A while back, when discussing the Yamaha T-85 in our FMtuners group was a hot topic, I dragged mine out to take a second look at the re-cap recipe and see what could be done about the ICs in the signal path. Actually the re-cap is a pretty straightforward operation with only one cap in the signal path, a bipolar near the output, leaving the power supply and decoupling locations left. I added the three caps used for voltage regulation and buffering on the front end board to the list and left the rest as previously changed. This left the four op-amps after the detector in the signal path, specifically ICs 203, 204, 205 and 210. The main issue at this point was that those ICs are 9-pin SIPs, not the typical 8-pin units. The schematic, at least the one I have, calls them NJM2041S and NJM2043S ICs. The IC block diagram indicates that they are all NJM2068S ICs, which are what are actually installed on the board. Also of note is that all these ICs are powered in balanced mode, a good thing IMHO. The search for an adapter board for 9-pin SIPs to 8-pin DIPs was less than successful, but in reviewing the block diagram it turns out that pins 1 and 9 are both V+ with an internal bridge connecting them together. Additionally, the pinout function sequence actually matches the typical 8-pin DIP configuration when installed with DIP pin 8 (V+) installed in wherever V+ is in the tuner board. In looking for a now easy-to-find adapter, Cimarron Technologies has one, but I wasn't too happy with the pins themselves and continued the search. I found this on eBay and they seemed to be well-built, plus there were additional solder pads for bypass caps on both V+/- and ground wire. They are also configured for both DIP and SOIC op-amps.
To make a long story short, using these adapters and OPA2134 op-amps with 0.01 µF bypass caps on V+/- all 4 OEM ICs were replaced. In looking at the board itself you will see that ICs 203, 204 and 205 only use ONE of the V+ pins which allows you to orient pin 8 on the adapter to wherever V+ is on the board. IC 210 is a little different in that it's powered off pin 9, but pin 1 is used as a passthrough to the PLL mono switch. So after you install the 8-pin adapter, you need to add a jumper from board through hole 9 to board through hole 1 which sends V+ power to Q264 and 265 through R439. In the OEM SIP9 installation, this connection is provided internally through the IC.
The adapter board has a nice, clean conformal coating and all solder pads were tinned. The addition of the bypass caps pads for V+/- and ground were laid out well, short lead on the hot side, convenient and easy to implement.
Right now the T-85 has about 100 hours on it and sounds pretty darn good, definitely better than factory, a touch quieter, though the Yammies are pretty quiet to begin with. The ICs were changed out one at a time and, to these aging ears, changing IC203 seemed to make the largest improvement, though all have an impact to some degree. If I were doing this for someone else or were interested in rolling different op-amps, I'd use sockets for the DIPs, at least on 210, which is the audio output op-amp. Don't forget the 3 'lytics in the front end voltage regulator/buffer.
You may also want to look at the mod in message #81890 in our FMtuners group which will allow the CSL and stereo to work at very low signal levels, and don't forget to read Bob's discussion beginning here about how the CSL works and its impact on reception. Lastly, if you're having to deal with an HD-encoded signal, the T-85 seems to recognize this as noise and you will see the 'Signal Quality' drop as you increase the IF bandwidth. If anyone wants additional info for the re-cap or the op-amp-ectomy, feel free to post a request in the group. Regards, JohnC" |
newaag
2/18/18 #81890
Here is the CSL Mod for the T-85, originally posted here by Ryan H. in message # 20230
This mod will allow CSL and stereo to work at very low signal levels, and overcome a lot of the hassles identified below.
I posted this a couple days ago, but it apparently got lost in the Yahoo system. Maybe it will show up tomorrow
Lately posting messages here are like sending a letter via US Mail.
"All you have to do is cut a jumper wire on the top of the PCB. Find
VR213 just above the right CSL IC chip on the front left section of
the tuner. To the right of VR213, snip the long vertical jumper
wire. It is the long one, not the short one. These instruction
were given to me courtesy of Steve McVie, and they do work. What
you are doing (if I recall the circuit correctly) is taking the FM
Noise amp out of the circuit. I traced out the TX-1000/2000 by hand
to work out the same thing, and can get that info as well if anyone
needs it.
Regards,
Ryan"
---In FMtuners@..., <rick.savas@...> wrote :
On the T-85, in auto search mode, it always wants to select the lowest IF bandwidth settings. search is basically a useless feature, apart from finding a strong signal, since it never really determines the optimum setting for the station. I guess they ran out of code space or did not bother to refine the algorithms ;-)
Does your signal indicator flip around the higher % leds? as an indication of multi-path or varying sig strength like it does on the T-85?
Also on the T-85, CSL only comes on when I get a signal ~>20%. With a fair bit of multi-path, it will flip CSL off, which is annoying, so I select fine tune, to defeat CSL, thankfully it never turns CSL back on, when in fine tuning mode. I did notice that it also wants to select mono, so I have to select very narrow filter to enable stereo again and then re-select the narrow filter, if I select wide it shuts off stereo again, since the signal level being displayed drops as well. |
Rick Savas
2/18/18 #81892
Thanks for the info, so assumption is that it is the connection to R493(1M). I am going to have a look at that signal from the noise amp to see how it operates. |
newaag
2/18/18 #81904
Never really went into great detail studying what it did, or why. But did it on my T-85, and TX-1000 and loved the way it allows CSL and stereo for low level RF signals. If you can give more details, that would be super.
Bob
---In FMtuners@..., <rick.savas@...> wrote :
Thanks for the info, so assumption is that it is the connection to R493(1M). I am going to have a look at that signal from the noise amp to see how it operates.
|
[email protected]
2/20/18 #81910
I have simulated the Yamaha noise circuit. It looks at noise in the detected signal above 90-100 kHz or so (I don't remember the cutoff frequency exactly). Since the bandwidth of an FM signal is 53 kHz, an output from the filter circuit indicates noise due to a weak received signal.
Don |
[email protected]
2/21/18 #81915
That mod appears to open up the connection of the noise detection circuit to the processor. So it should trick the processor into thinking the received signal is never noisy. |
newaag
2/21/18 #81916
That also where significant IBOC sideband power lies, above 100 kHz.
Bob |
