Re: 6HS6 Price and Availability
Thanks for this no-guesswork essay, Steve. ?Maybe when time avails, quantitative testing will be done and published.
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73, Michael, N4KZO
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Re: 6HS6 Price and Availability
Roger that, John.
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73, Michael, N4KZO
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Re: 6HS6 Price and Availability
Thank you, Gary: a little good engineering ¡ª love it.
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73, Michael, N4KZO
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Re: 6HS6 Price and Availability
Good work, Dave. ?Thank you for your efforts in experimental tests to resolve this drama: learning, learning, we never stop learning
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73, Michael, N4KZO
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Re: 6HS6 Price and Availability
Thank you, Kim. ?Doing a little looking around, I¡¯ve found bunches and grunions of NOS 6AH6 tubes: say $3 - $4 EACH. ?You answer which immediately comes to my mind, as to why the 6HS6 was chosen by Drake engineering. ?With the present atmospheric noise level, the 6AH6 should work fine, if present; when it gets quiet again, I can check use of the 6AH6 as an experiment as I think I have all 6HS6¡¯s. ?But, as Peter has elucidated, we don¡¯t need to concerned; I¡¯m working on getting a B-line going and haven¡¯t assessed a need, but I¡¯m sleeping easy: a good lesson.
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73, ?Michael, N4KZO
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Re: 6HS6 Price and Availability
Good job, Peter. ?Good lesson for me. Thank you.
zzzzzzzzzzzzzzzzzzz
73, Michael, N4KZO
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Re: Using the PLJ-6LED digital display with the R4C
P.S. ? I would first start with only Q1 to rule out any effect cable capacitance is having on the RF voltage level between INJ and the digital display.? The display spec sheet indicates that it should function with way less than you measured at INJ. If necessary, then add Q2. ? Paul, W9AC ?
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From: [email protected] <[email protected]> On Behalf Of Paul Christensen via groups.io
Sent: Wednesday, January 8, 2025 8:13 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Using the PLJ-6LED digital display with the R4C? Floyd, ? WB6OGD pointed to a good go-to reference from Elecraft.? Have a look at the schematic on p. 27 and refer to Q1 and Q2.? Q1 (J310) has a gain less than unity as a source follower.? However, it¡¯s then amplified by Q2 (MPSH10) in a collector-feedback circuit formed by R3/R6.? Install at the INJ point.? Use capacitive coupling from the Q2 collector to your new digital display. ?
? Paul, W9AC ? ? Possibly consider a J310 JFET as a common-source amp placed right at the source of the INJ jack. Resistors chosen for a gain of A = 2 (6 dB) to get over the minimum RF sample voltage requirement. ? ? The JFET unloads the INJ line to the Hi-Z gate and that isolates the INJ source from cable capacitance to the freq. counter.? With adequate PS decoupling, probably a half-dozen parts are needed, mounted either on a 5-6 lug terminal strip or Vector board.? ? The common I.F. output buffers often seen are common-drain source-followers with a gain of less than 1.0.? That won¡¯t work in this instance to solve the problem.? ?
Paul, W9AC ? That sounds like the solution, Paul, but I'm afraid I'm not capable of doing that probably simple design.? Can you point me to an existing example, or, do a simple design ?? Not sure why I seem to be the only one who ever had a problem with the available INJ signal level, but maybe others haven't actually tested their configuration on 10 and 15 meters with the T4X connected to the INJ cable.? Without that connection, the signal level is adequate to provide a stable readout in my case on the highest bands. ? 73, Floyd - K8AC??
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Re: 6HS6 Price and Availability
Drake¡¯s R4 series RF amp evolution is interesting.? It began with a 12BZ6 in the original R4/R4A, changed to a 6HS6 in the R4B, ending with a 6BA6 in the R4C.? The latter is commonly found in many IF circuits, including Drake but not too often used as the 1st RF amp.? Can anyone guess as to Drake¡¯s impetus for the change? ?Seems like all three tube types were available at the beginning of R4 production.? ? Paul, W9AC
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Re: AFG/RFG controls R4C (W1ES)
Funny thing is, lately, my TR7 is the rig that most benefits from lowering the RF gain a tad. Lots of popping on fast AVC, otherwise. The A's and B's areen't as bad. The C is in between...
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with Proton Mail secure email.
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On Wednesday, January 8th, 2025 at 7:48 PM, Jim Shorney via groups.io <jimNU0C@...> wrote: I guess you probably don't need to lower your noise floor for any reason. You must have DSP ears. I bet you can copy RTTY in your head too.
On Wed, 08 Jan 2025 14:19:37 -0800
"N3 EG via groups.io" n3eg@... wrote:
The RF Gain control has always been the most useless thing to put on a radio.
--
73
-Jim
NU0C
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Re: If you're going to be sloppy....
Oops.? I forgot about the FS-4 and I only took a quick peek -- didn't notice the shipping.? Yeah, free shipping at that price qualifies as a bargain!? If I was in the market, I probably would have paid more attention...
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Wednesday, January 8th, 2025 at 7:55 PM, Gary WB6OGD via groups.io <winbladgary@...> wrote:
Come off?
That is the rare FS-4 sticker overlay everyone is looking for!
Implies there are no extra crystals inside but it has been used with the FS-4.
$220 for a nice looking, working T-4XC is a good deal with free shipping..? it sold quickly I guess.
73,
Gary
WB6OGD
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Re: 6HS6 Price and Availability
No, James, nobody "jacked up" the price. As I previously mentioned, the price for this tube has been high for at least 30 years and probably longer.? There's no cabal of n'e'e'r-do-wells conspiring to deprive poor Drake aficionados of an extra $10 and nobody is buying real estate in KP2 with their proceeds.? The 6HS6's price is market-driven and a part of that is due to some tube audio companies using this tube in their lineup (Fisher being one).? There are more tube audio folks than tube radio folks, so we are splitting demand.
Drake initially was using the 6AU6 for both the first Mixer and the Premixer.in both the R-4 and the first T-4's.? They fairly quickly changed over to the 6HS6.? Though the actual decision-making is lost to the sands of time,it has been noted by others that the 6HS6 has better overall performance over the 6AU6,? The 6AH6 has nearly the same performance as the 6AH6 but, again, it's unknown why Drake chose one over the other.? The price at the time was likely a factor but not the only factor, as if price was the only factor, they would have stuck with the 6AU6 as it was available from nearly every vendor in massive quantities.? The 6HS6 was not as common even when they were current technology.
Here's the thing: most owners now use these rigs for relatively casual use.? They still hold their own (My opinion of my B Line is that it's a better rig than my Collins S Line, and there are reasons for that that I won't go into here).? These were used in contest stations up to the early 70's, when the C Line went into production and "brick-wall" filtering became a "must-have".? Under those conditions, the performance of the 6HS6 could reveal itself in the middle of a pileup.? I haven't made actual comparisons or tests.? Only subjective comparisons asnd my experience in the late 80s through around 1990, when I used a C Line for DXing and contesting as my only rig.
Today, when my 6HS6's are gone, I will gladly use 6AH6's in their place.? I have a small stock of 6AH6's (as well as 6HS6's, which I am not keen on selling even for $40). I have done limited testing on my R-4B with the 6AH6 subbed into both V2 and V8.? Steady-state signals reveal the same performance with either tube.? That isn't to say that IMD, etc., will also be the same but anyone interested can do the swap, hook up the equipment and publish their findings.
We should be happy that we only have that as the only uncommon tube in the linup (but don't get me started on 12BZ6 and some other early stuff).? Heathkit owners have to deal with Compactrons and some other strance stuff, so we are good here.
As always, YMMV.
73,
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Wednesday, January 8th, 2025 at 5:12 PM, James Barrie via groups.io <barrie43@...> wrote:
I have used a 6AH6 in my R-4A for a year now with no issues. Maybe there was something magical about the 6HS6 when Drake decided to use it. My guess it was the cheapest tube that would work.
And I also suspect that a couple of tube vendors cornered a bunch of 6HS6s and jacked the tube's prices up blaming the audio people for the "scarcity".
It is pretty easy to make a solid state mixer. Unlike amplifiers, that need just a certain amount of amplification, extra AVC inputs, etc., mixers are
basically non-linear choppers. They just need enough gain to chop and enough voltage tolerance for the circuit they are in.
My very first experiment was a J-310 FET(the only FET I had) plugged into the R-4A Pre-mixer socket. I only had to disconnect the +150V plate supply resistor and hook it to about 18VDC(?). Worked fine though hooking it to the T-4X and selecting XMTR control might have blown it.
I researched more (stole designs and modded) and now have a plug in tube replacement. Works great.
Attached is what I think I am running now. I also attached a 6AU6 replacement from the Collins site.
Beats trying to buy expensive, possibly bad old tubes. YMMV.
My 6HS6 is now safe and part of my 401K IRA.. hi hi...
73,
Gary
WB6OGD
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Re: Using the PLJ-6LED digital display with the R4C
Floyd, ? WB6OGD pointed to a good go-to reference from Elecraft.? Have a look at the schematic on p. 27 and refer to Q1 and Q2.? Q1 (J310) has a gain less than unity as a source follower.? However, it¡¯s then amplified by Q2 (MPSH10) in a collector-feedback circuit formed by R3/R6.? Install at the INJ point.? Use capacitive coupling from the Q2 collector to your new digital display. ?
? Paul, W9AC ?
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From: [email protected] <[email protected]> On Behalf Of Floyd - K8AC via groups.io
Sent: Wednesday, January 8, 2025 3:38 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Using the PLJ-6LED digital display with the R4C? Possibly consider a J310 JFET as a common-source amp placed right at the source of the INJ jack. Resistors chosen for a gain of A = 2 (6 dB) to get over the minimum RF sample voltage requirement. ? ? The JFET unloads the INJ line to the Hi-Z gate and that isolates the INJ source from cable capacitance to the freq. counter.? With adequate PS decoupling, probably a half-dozen parts are needed, mounted either on a 5-6 lug terminal strip or Vector board.? ? The common I.F. output buffers often seen are common-drain source-followers with a gain of less than 1.0.? That won¡¯t work in this instance to solve the problem.? ?
Paul, W9AC ? That sounds like the solution, Paul, but I'm afraid I'm not capable of doing that probably simple design.? Can you point me to an existing example, or, do a simple design ?? Not sure why I seem to be the only one who ever had a problem with the available INJ signal level, but maybe others haven't actually tested their configuration on 10 and 15 meters with the T4X connected to the INJ cable.? Without that connection, the signal level is adequate to provide a stable readout in my case on the highest bands. ? 73, Floyd - K8AC??
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Ah the Analog Guru Jim Williams. I will always be in awe of the insight and knowledge that he had. On Tue, Jan 7, 2025 at 8:36?AM John E. Beck via groups.io <wb0rxl@...> wrote:
I would be happy to share it. It's always a work in progress, but let me clean it up a bit.
John
WB0RXL
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Re: If you're going to be sloppy....
Come off?
That is the rare FS-4 sticker overlay everyone is looking for!
Implies there are no extra crystals inside but it has been used with the FS-4.
$220 for a nice looking, working T-4XC is a good deal with free shipping..? it sold quickly I guess.
73,
Gary
WB6OGD
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Re: AFG/RFG controls R4C (W1ES)
I guess you probably don't need to lower your noise floor for any reason. You must have DSP ears. I bet you can copy RTTY in your head too. On Wed, 08 Jan 2025 14:19:37 -0800 "N3 EG via groups.io" <n3eg@...> wrote: The RF Gain control has always been the most useless thing to put on a radio. -- 73 -Jim NU0C
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Re: If you're going to be sloppy....
It should come off without too much trouble.? An okay price if it's actually working.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Wednesday, January 8th, 2025 at 7:28 PM, John K5MO via groups.io <johnk5mo@...> wrote:
... do so on the front panel?
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This is a shame.
I wonder if it has the crystals that the overlay suggests it might.? Rest of the rig looks well worn too and priced accordingly.? Too bad some care wasn't taken in placing the overlay.
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https://www.ebay.com/itm/186861604746
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If you're going to be sloppy....
... do so on the front panel?
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This is a shame.
I wonder if it has the crystals that the overlay suggests it might.? Rest of the rig looks well worn too and priced accordingly.? Too bad some care wasn't taken in placing the overlay.
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https://www.ebay.com/itm/186861604746
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Re: 6HS6 Price and Availability
If you try them as a sub, please let us know how it goes.
John K5MO
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Re: 6HS6 Price and Availability
This tube (6AH6) intrigued me, so I went down today to the supply store and bought a couple to test in place of the 6136/6HS6 tubes I'm currently using as mixers.
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I confirm they work fine as mixers in the R-4x in place of the 6HS6. I measured the heater voltages again this afternoon and I show 12.68VAC on the 6EH5 and 6.31VAC on the 6AH6, so completely in spec with the series filaments.
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So forget the expensive 6HS6 and just buy the cheapie 6AH6 instead ($3 each at my local electronics store).? Dave
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Re: AFG/RFG controls R4C (W1ES)
I also use the RF gain control on my 75A-2 & 75A-4 receivers quite regularly
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On Jan 8, 2025, at 4:46?PM, Richard Knoppow via groups.io <1oldlens1@...> wrote:
? All I can say is that I disagree. There are times when an RF gain control is quite useful. On radios where there is a good AVC the RF gain acts as a variable "delay" setting the threshold of the AVC.
BTW, if you think any S meter is accurate you are fooling yourself.
On 1/8/2025 2:19 PM, N3 EG wrote:
On Wed, Jan 8, 2025 at 03:13 AM, Joseph K7CBR wrote:
Are you still using electricity?
The RF Gain control has always been the most useless thing to put on a radio. It's like a high/low switch on a vacuum cleaner, which should be called "Clean/Less Clean." In the case of HF radios, it should be called the Ignore Weak Signal Stations And Screw Up Your S-Meter Reading Control.
I've never found a good reason to use it in at least 52 years of HF listening, and it's totally useless on 10 meters and up.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
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Paul Christensen
Gary WB6OGD
Jim Shorney
Thomas W9TAB