Thanks. This was based off a Marshall jcm. Found the schematic online. I can share it if you’d like
toggle quoted message
Show quoted text
On Mar 25, 2021, at 11:28 PM, VE7PS <ve7ps@...> wrote:
?
Nice job Brian!? Looks like an L-7-PS!? As a multi Strat
player/owner I get it! Been wanting to re-create a Fender amp
someday.
73
Peter
VE7PS
On 2021-03-25 6:23 p.m., Brian Smith
wrote:
Pardon me. This isn’t exactly Drake. I just finished my first
build from scratch. A tube bass guitar preamp. Since I love Drake
gear, I decided to make it remotely resemble an AC4 or L4PS. Two
12AX7s and one 12DW7. Just wanted to share it.?
|
Re: L75 Amp Main Power Switch Availability
I'm not going to waste time debating trivia with you. I just don't want the audience to get the impression that the L-4B is some pathetic POS that doesn't even deserve to be on 11 Meters based on your rantings. The fact is that a countless number of these amps have been in service for decades and they do the job they were intended to do as-is. 73 -Jim NU0C On Tue, 23 Mar 2021 08:51:49 -0700 "Jim VE7RF" <jim.thom@...> wrote: On Sun, Mar 14, 2021 at 08:21 PM, Jim Shorney wrote:
<Hmm... They survived through three engineering generations and served the
purpose over the decades of real world use. Real HV fuses are expensive
for a new build. Even the great W8JI <espouses the use of fault limiting
resistors, although he prefers higher values.
<73
<-Jim
<NU0C
##? ?You won't see any amps other than drake, using a .82 ohm? @? 2 watt? resistor.....for a... 'hv? fuse'.? ?New, correctly sized? HV? fuses are cheap, and meet? ?UL /? CSA? standards.? ?Drake could have bought thousands of em? at whole sale prices.? ?W8JI? typ will use 10 ohm,? or? 20? ohm max, for the? current limiting resistor (aka...'glitch resistor').? ?ARRL handbook? sez to use? 10-15 ohms? per KV.? ?After building? 38? x hb? B+? supplies over the years, and experimenting with different value glitch resistors,? I settled on? 50 ohms, regardless of the? actual? B+? value.? ?But it's a two edged sword.? ?Higher values will limit fault current to a lower value.... BUT dissipate more heat, depending on? mode, and how much average plate current involved.? ?Higher value? glitch resistors? also have a higher? V drop? across them...? ( which will increase even more, with higher plate currents).
##? In? L4B? size amps,? ?with say? 2650 vdc no load..and a fault occurred,? it's then just 2650 /? 50 ohms =? ? 53 amps of fault current.? And? ?53 amps of fault current will open off that? BUSS? 750 ma HV fuse in? < 2 msecs? every time.? ?On a L4B, with? 800 ma peaks on? ssb,? the? V drop on peaks is .8? X? 50 ohms? = 40 vdc? V drop on the loaded? B+.? ? Average plate current on ssb mode is? typ? 400 ma( with processing).? ?(.4 X.4 )? ?X 50 ohms =? ? 8 watts dissipation? in the? 50 ohm glitch R.? ?( and? 32 watts if a? 800 ma? dead cxr, like tuning up with a cxr).? ?Hence my use of a? simple? 50 ohm, 50 watt wire wound? for the glitch? R.
##? On the bigger? HB? B+? supplies, with a lot more filter C,? ?I use globar type AS? resistors.? The? AS types are designed for glitch service, and will handle a lot of joules of? energy...and also a lot of HV.? Typ,? 4 x 200 ohm, type? AS? resistors are wired in parallel..and also fan cooled.? ?But that's what's required for 5-8 kv dc? supplies..and tubes that? suck 1.5? to 3 amps of plate current.? ?3 amps? ccs? into 50 ohms? =? ?450 watts, which is a bunch.? The type? AS? resistors are? 18"? long x 1.5"? diam,? rated for? 225 watts each /? 900 w? total.? They run hot when used in ccs modes.? ?Lower? duty cycle modes like? ssb is a non issue,? only? ?1/4 the? dissipation...same as? the 50 ohms used in the? L4B? B+? supply.
Jim? VE7RF
|
Wow!? OK no excuses but time now...I have to build one of these!
73
Peter
VE7PS
On 2021-03-25 8:12 p.m., wb6ogd wrote:
toggle quoted message
Show quoted text
On Thu, Mar 25, 2021 at 05:31 PM, VE7PS wrote:
...as WB6OGD has come up with an el-cheapo modern
equivalent of the Drake FS-4 frequency synthesizer that you can
build easily for about $30.?
As Peter says, no need for xtals anymore, The SPR-4 would be
great to have..wish I could find a cheap one!?
And, I have the FS-4 cost down to more like $11 now,? hi hi.
I think we could even add passband tuning... the Si5351
synthesizer we use actually has 3 outputs and we are only using
one for the band crystal
frequency.? Another could replace the BFO and with some Arduino
code, we could vary both, one up and the other down...? PASSBAND
TUNING!
And, by counting the PTO frequency and coding, we could send an
Injection signal to the T-4X without need for the Drake
transceive adapter.
73,
Gary
WB6OGD
|
Nice job Brian!? Looks like an L-7-PS!? As a multi Strat
player/owner I get it! Been wanting to re-create a Fender amp
someday.
73
Peter
VE7PS
On 2021-03-25 6:23 p.m., Brian Smith
wrote:
toggle quoted message
Show quoted text
Pardon me. This isn’t exactly Drake. I just finished my first
build from scratch. A tube bass guitar preamp. Since I love Drake
gear, I decided to make it remotely resemble an AC4 or L4PS. Two
12AX7s and one 12DW7. Just wanted to share it.?
|
On Thu, Mar 25, 2021 at 05:31 PM, VE7PS wrote:
...as WB6OGD has come up with an el-cheapo modern equivalent of the Drake FS-4 frequency synthesizer that you can build easily for about $30.?
As Peter says, no need for xtals anymore, The SPR-4 would be great to have..wish I could find a cheap one!?
And, I have the FS-4 cost down to more like $11 now,? hi hi.
I think we could even add passband tuning... the Si5351 synthesizer we use actually has 3 outputs and we are only using one for the band crystal
frequency.? Another could replace the BFO and with some Arduino code, we could vary both, one up and the other down...? PASSBAND TUNING!
And, by counting the PTO frequency and coding, we could send an Injection signal to the T-4X without need for the Drake transceive adapter.
73,
Gary
WB6OGD
|
Re: I’ll leave this here...
Welp, someone wanted it.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Steve Wedge, W1ES/4 via groups.io" <w1es@...>
To: [email protected]
Sent: Thursday, March 25, 2021 9:17:04 PM
Subject: Re: [DRAKE-RADIO] I’ll leave this here...
Someone adapted. It’s that simple.
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from ProtonMail Mobile
On Thu, Mar 25, 2021 at 11:34, n4buq <n4buq@...> wrote:
It does make me wonder how that came to be. If that was a retrofit, then
I'd think the original meter had a different hole pattern but maybe not.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Joe Wolfe" <w7rkn.7@...>
To: [email protected]
Sent: Thursday, March 25, 2021 10:30:21 AM
Subject: Re: [DRAKE-RADIO] I’ll leave this here...
WOW…..I have never seen a W4 with that meter!
Joe – W7RKN
From: [email protected] [mailto:[email protected]] On Behalf Of
Steve
Wedge, W1ES/4 via groups.io
Subject: [DRAKE-RADIO] I’ll leave this here...
Such a deal! Gave me a chuckle.
<>
Steve Wedge, W1ES/4
|
Re: I’ll leave this here...
Someone adapted. It’s that simple.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent from ProtonMail Mobile
On Thu, Mar 25, 2021 at 11:34, n4buq < n4buq@...> wrote: It does make me wonder how that came to be. If that was a retrofit, then I'd think the original meter had a different hole pattern but maybe not.
Thanks,
Barry - N4BUQ
----- Original Message -----
> From: "Joe Wolfe" <w7rkn.7@...>
> To: [email protected]
> Sent: Thursday, March 25, 2021 10:30:21 AM
> Subject: Re: [DRAKE-RADIO] I’ll leave this here...
>
> WOW…..I have never seen a W4 with that meter!
>
>
>
> Joe – W7RKN
>
>
>
> From: [email protected] [mailto:[email protected]] On Behalf Of Steve
> Wedge, W1ES/4 via groups.io
> Subject: [DRAKE-RADIO] I’ll leave this here...
>
>
>
> Such a deal! Gave me a chuckle.
>
>
>
> https://www.ebay.com/itm/Rare-Vintage-Drake-W-4-ham-radio-wattmeter-W4-/184726059567
> <https://www.ebay.com/itm/Rare-Vintage-Drake-W-4-ham-radio-wattmeter-W4-/184726059567?_trksid=p2349624.m46890.l49292>
>
>
>
> Steve Wedge, W1ES/4
>
>
>
>
>
>
>
>
>
|
Re: I’ll leave this here...
Finally, a post from someone who gets it.?
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent from ProtonMail Mobile
On Thu, Mar 25, 2021 at 11:30, Joe Wolfe < w7rkn.7@...> wrote: WOW…..I have never seen a W4 with that meter! ? Joe – W7RKN ? ? Such a deal! ?Gave me a chuckle.?
|
Re: I’ll leave this here...
Please don’t use the word, “greed”.?
The market has adjusted to the conditions.?
There are no hamfests; there are virtually no cheap venues to sell items. Selling via eBay costs money and labour.?
Nobody wants to work for free.?
Selling via eBay adds 20%, plus shipping.?
At any rate, a price for an item is what a willing buyer and seller are willing to exchange at.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent from ProtonMail Mobile
On Thu, Mar 25, 2021 at 10:47, Billy NN5EE via groups.io < bb99olreg@...> wrote: [Edited Message Follows]
Typical Ebay these days as previous threads indicated. Read this article--??- this morning. Apart from the greed that Ebay shows today Covid has altered the landscape of global commerce to the point that interactive industries are adversely impacted. The HR used rig markets are potentially impacted also. Can't wait for the day when I can attend hamfests even with mask. Vacinated and ready!
|
I have had my SPR-4 for about 20 years and the SPR-4 is a great receiver with low current drain if the dial lights are turned off. Be prepared to pay for any additional crystals that you might need or want. A frequency synthesizer is also an option.
Dan Steinhoff - W7UP
|
Pardon me. This isn’t exactly Drake. I just finished my first build from scratch. A tube bass guitar preamp. Since I love Drake gear, I decided to make it remotely resemble an AC4 or L4PS. Two 12AX7s and one 12DW7. Just wanted to share it.?
|
I have two. I grade them Marvelous Plus. They are fully crystaled, and I have an FS-4. I use the internal speakers.
David, WA7ZYQ ?C’est la vie, c’est la guerre, ?vive la salade de pommes de terre.
toggle quoted message
Show quoted text
On Mar 25, 2021, at 1:26 PM, Matt Jodz <mfjodziewicz@...> wrote:
|
Matt:
Welcome to the wonderful world of Drake radio..... is this your 1st?
Make sure you get the AC power cord with and that it is in good
shape.? Check carefully at the molded plug that goes into the radio
as it tends to fail there.? Treat the AC cord with kid gloves, as
that plug is VERY hard, of not impossible, to replace.? There are
suitable workarounds if it goes bad.? Check back with us if/when
that happens.
The SPR-4 is a good all round SW receiver, in my opinion, though it
lacks the selectivity choices or performance that an R-4C, or even
the earlier 4-line receiver offer, but that said...it does pretty
well with what it has for general snooping around the bands.? They
normally don't come with a full set of xtals so one with the ham
bands added is worth more in my opinion.? But....fear not if there
are no ham band xtals....as WB6OGD has come up with an el-cheapo
modern equivalent of the Drake FS-4 frequency synthesizer that you
can build easily for about $30.? Plans are on this group's file
pages.? That will give you FULL coverage of the SW bands to 30 Mhz.
There is a noise blanker available, but they are rare as hen's teeth
and cost (almost) more than a chicken farm!? Easier to chase your
noise sources if you have that issue.? Nice to have the xtal
calibrator option, which plugs into one of the back corners of the
chassis.? Hopefully it has that.
PTO is the same as the C-line with the same dial issues regarding
calibration and PTO cleaning, though not likely needed.? Just make
sure the dials aren't rubbing together, or against anything else
either.
Check the electrolytic caps under the chassis for any signs of
bulging/failure and replace as needed.? I have had to replace some
on the audio board.
There are two verions of the audio board depending on serial
number.? Early ones used a couple of odd transistors that is pretty
hard to find these days.
Plan on putting in new blue and/white dial and meter filters to get
that "Drake blue" back again.? The white filters tend to yellow with
age creating a more greenish tint.? You can use drop-in Cointaker
#47 warm white LED replacements for the #47 bulbs at under $1 each.?
You will need 3 in the SPR-4.? The dial filters will also need to be
cut out by hand with a sharp X-acto or utility knife for the Xtal
selector window.? Save the old one to use as a template.
If the vinyl-like finish on the cabinet has faded, and cleaning
doesn't help, an application of a good black shoe polish, followed
by a good drying period and a buff will make it look a lot better!?
AGC calibration in the SPR-4 is very key to making the radio sound
good.? Always worth checking that part of the manual and running
through the alignment.
Good luck!
73
Peter
VE7PS
On 2021-03-25 1:26 p.m., Matt Jodz
wrote:
toggle quoted message
Show quoted text
Gentlemen,
? ? ?I have the opportunity to get a Drake SPR-4 in excellent
physical and working condition but would like to hear what the
group thinks of this Solid State rig as my experience has only
been with the tube type Drakes.? The wife of course thinks I am
crazy (of this no doubt) but any comments you may offer may help
to sway her.
? ? ?Thanks ahead of time.
? ? ? Matt ND7MJ
|
Re: I’ll leave this here...
I have a C-4 but I'd consider it at $25.? That's basically a hamfest price for a generic non-Bird wattmeter.
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Thursday, March 25, 2021 9:52 AM, VE7PS <ve7ps@...> wrote:
Ha ha - me too!? Well I guess if that's what you need to do.? But at
$135?
PS
On 2021-03-25 6:44 a.m., Steve Wedge,
W1ES/4 via groups.io wrote:
Such a deal! ?Gave me a chuckle.?
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent from ProtonMail Mobile
|
Gentlemen,
? ? ?I have the opportunity to get a Drake SPR-4 in excellent physical and working condition but would like to hear what the group thinks of this Solid State rig as my experience has only been with the tube type Drakes.? The wife of course thinks I am crazy (of this no doubt) but any comments you may offer may help to sway her.
? ? ?Thanks ahead of time.
? ? ? Matt ND7MJ
|
Re: I’ll leave this here...
Okay. I've never owned one so wasn't sure about the hole pattern.
Yes - agree that they could've at least dressed up the paint and hardware a bit but that'd be easy enough to do if someone wanted it badly enough (which I do not).
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Mark KIllmon" <mark@...>
To: [email protected]
Sent: Thursday, March 25, 2021 11:18:01 AM
Subject: Re: [DRAKE-RADIO] I’ll leave this here...
Nope. Same pattern at least. 120 degrees is 120 degrees. Same sized
meter body—a drop-in replacement..
But c'mon. At least repaint the meter and use decent hardware. :-P
*73, Mark - K4SO
www.k4so.com*
*
*
*
*
On 3/25/2021 11:34 AM, n4buq wrote:
It does make me wonder how that came to be. If that was a retrofit, then
I'd think the original meter had a different hole pattern but maybe not.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Joe Wolfe" <w7rkn.7@...>
To: [email protected]
Sent: Thursday, March 25, 2021 10:30:21 AM
Subject: Re: [DRAKE-RADIO] I’ll leave this here...
WOW…..I have never seen a W4 with that meter!
Joe – W7RKN
From: [email protected] [mailto:[email protected]] On Behalf Of
Steve
Wedge, W1ES/4 via groups.io
Subject: [DRAKE-RADIO] I’ll leave this here...
Such a deal! Gave me a chuckle.
<>
Steve Wedge, W1ES/4
|
Re: I’ll leave this here...
Nope. Same pattern at least. 120 degrees is
120 degrees. Same sized meter body—a drop-in replacement..?
But c'mon. At least repaint the meter and
use decent hardware. :-P
73, Mark - K4SO
On 3/25/2021 11:34 AM, n4buq wrote:
toggle quoted message
Show quoted text
It does make me wonder how that came to be. If that was a retrofit, then I'd think the original meter had a different hole pattern but maybe not.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Joe Wolfe" <w7rkn.7@...>
To: [email protected]
Sent: Thursday, March 25, 2021 10:30:21 AM
Subject: Re: [DRAKE-RADIO] I’ll leave this here...
WOW…..I have never seen a W4 with that meter!
Joe – W7RKN
From: [email protected] [mailto:[email protected]] On Behalf Of Steve
Wedge, W1ES/4 via groups.io
Subject: [DRAKE-RADIO] I’ll leave this here...
Such a deal! Gave me a chuckle.
Steve Wedge, W1ES/4
|
Re: DR7 fitting partial success.
Hi Mike, The display looks good now. Glad to see you have it working.
I have some KW equipment here awaiting restoration. The KW202/204 pair, KW2000E w/PS, KW109 and a few other items.
Most of the KW equipment, in North America, came in through Canada so it shows up here from time to time.
73
Roger VE7LB
|
Re: I’ll leave this here...
It does make me wonder how that came to be. If that was a retrofit, then I'd think the original meter had a different hole pattern but maybe not.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Joe Wolfe" <w7rkn.7@...>
To: [email protected]
Sent: Thursday, March 25, 2021 10:30:21 AM
Subject: Re: [DRAKE-RADIO] I’ll leave this here...
WOW…..I have never seen a W4 with that meter!
Joe – W7RKN
From: [email protected] [mailto:[email protected]] On Behalf Of Steve
Wedge, W1ES/4 via groups.io
Subject: [DRAKE-RADIO] I’ll leave this here...
Such a deal! Gave me a chuckle.
<>
Steve Wedge, W1ES/4
|
Re: I’ll leave this here...
WOW…..I have never seen a W4 with that meter! ? Joe – W7RKN ? ? Such a deal! ?Gave me a chuckle.?
|
Jim Shorney
Gary WB6OGD
Dan Steinhoff - W7UP