Drake R8 question
Pete KE9OA
bandpass filter schematic, I notice a T type of attenuator that consists of
two 270 ohm series resistors, with a 330 ohm shunt resistor on the MW filter
section.
Am I dreaming, or did Drake really dumb down the design with a full time
attenuator on the MW band? If this is the case, it looks like I have yet
another project.
Pete
Telamon
"Pete KE9OA" <p.gi...@comcast.net> wrote:
On the R8 I think they also don't allow you to turn on the pre-amp.
--
Telamon
Ventura, California
Drakefan
I don't see that attenuator on the MW (0.5-1.5-Mhz) bandpass filter for
the R8'B'. The MW bandpass circuit on the 'B' looks like all the other
bands but with different component values of course.
Pete KE9OA
they may have installed an attenuator on that model. I will give Drake a
call this morning.
Pete
"Drakefan" <Drak...@bluesky.net> wrote in message
news:Fluxj.7931$xg6.6122@trnddc07...
dxAce
Pete KE9OA wrote:
> That sounds good.............the service manual I have is for the R8E, so
> they may have installed an attenuator on that model. I will give Drake a
> call this morning.
I get the same S meter readings on the R8, R8A and R8B. The attenuator can be
kicked in on all three, difference being is that the pre-amp can be used in the
A & B but not on the R8.
dave
Different first mixer?
Pete KE9OA
after the input switching diode for the MW range, I see the attenuator. I
just talked to Bill Frost, over at Drake, and he tells me that all of the
front ends are the same. If this is the case, it shouldn't be too hard to
remove it. They may have pulled a tricky one, the JRC did with the MW range
on the
NRD-515.
On another note, I have built the first engineering prototype of the new
Palstar active loop antenna. There was a bit of a delay receiving the
ferrite rod stock, but that should be coming in, in the next few days or
so.
I still need a few PCB footprint files.........after this, I will be able to
do the board layout. It shouldn't take more than a few hours to do.
Pete
"dave" <not...@nowhere.com> wrote in message
news:13sdc5g...@corp.supernews.com...
Pete KE9OA
Cedar Rapids, there was a fellow named Steve in Michigan that had some sort
of intermod problem with a Sony 6800W. Were you that person, or was it
another Steve?
Pete
"dxAce" <dx...@milestones.com> wrote in message
news:47C6A6C7...@milestones.com...
dxAce
Pete KE9OA wrote:
> Thanks Steve............I appreciate that. Years ago, when I was living in
> Cedar Rapids, there was a fellow named Steve in Michigan that had some sort
> of intermod problem with a Sony 6800W. Were you that person, or was it
> another Steve?
Not me Pete, I've never had a 6800W.
Pete KE9OA
I am going to take a look at that R8 in a little while and see how it works.
My friend is also bring over an R7 S/N 3400 range, with a PLL unlock
problem. Just what I always wanted to work on...........another one!
Pete
"dxAce" <dx...@milestones.com> wrote in message
news:47C6DB4B...@milestones.com...
dxAce
Pete KE9OA wrote:
> Thanks Steve,
>
> I am going to take a look at that R8 in a little while and see how it works.
> My friend is also bring over an R7 S/N 3400 range, with a PLL unlock
> problem. Just what I always wanted to work on...........another one!
Keep those R7's running.
Pete KE9OA
now......................cleaning the contacts on the regulator board got
the low end of the low band VCO working....................the high band VCO
only works up at MHz. I am thinking, that with the high S/N, it looks like
the owner of this radio sold the R7A face plate to somebody and installed an
R7 faceplate on this radio before he moved it out.
I played a little bit with the R8...........now I see why everybody likes it
so much. I think I will modify it so the preamp works on all ranges, that
is, after I remove that pesky MW attenuator. Nice receivers.
Pete
"dxAce" <dx...@milestones.com> wrote in message
news:47C6E4E3...@milestones.com...
dxAce
Pete KE9OA wrote:
> U bet you............I've got it apart right
> now......................cleaning the contacts on the regulator board got
> the low end of the low band VCO working....................the high band VCO
> only works up at MHz. I am thinking, that with the high S/N, it looks like
> the owner of this radio sold the R7A face plate to somebody and installed an
> R7 faceplate on this radio before he moved it out.
> I played a little bit with the R8...........now I see why everybody likes it
> so much. I think I will modify it so the preamp works on all ranges, that
> is, after I remove that pesky MW attenuator. Nice receivers.
I just saw a message on the Drake reflector wondering about a possible change
due to the serial number. Thought it must be an R7A vs. an R7.
Name Dan, by any chance?
Drakefan
> No, it is using the same 1st mixer. In my service manual for the R8E, right
> after the input switching diode for the MW range, I see the attenuator. I
> just talked to Bill Frost, over at Drake, and he tells me that all of the
> front ends are the same. If this is the case, it shouldn't be too hard to
> remove it. They may have pulled a tricky one, the JRC did with the MW range
> on the
> NRD-515.
They must all be the same *except* for the 'E' model. I can see why they
might have wanted to attenuate the MW band in a receiver made for use in
Europe where the MW signals can be very high at times. Have you actually
confirmed that your model has the MW attenuator?
JoanD'arcRoast
<p.gi...@comcast.net> wrote:
> U bet you............I've got it apart right
> now......................cleaning the contacts on the regulator board got
> the low end of the low band VCO working....................the high band VCO
> only works up at MHz. I am thinking, that with the high S/N, it looks like
> the owner of this radio sold the R7A face plate to somebody and installed an
> R7 faceplate on this radio before he moved it out.
> I played a little bit with the R8...........now I see why everybody likes it
> so much. I think I will modify it so the preamp works on all ranges,
If you do this mod, would you post a how-to? I have an R8; I would like
to make the pre-amp work on LW NDBs.
thanks,
-j
Pete KE9OA
Pete
"dxAce" <dx...@milestones.com> wrote in message
news:47C6ECAC...@milestones.com...
Pete KE9OA
fighting the flu AND fixing that R7
Pete
"JoanD'arcRoast" <JoanD'arcR...@biteme.org> wrote in message
news:280220081240487120%JoanD'arcR...@biteme.org...
dxAce
Pete KE9OA wrote:
> How did you guess?????????????????????????
They don't call me 'Ace' for nothing!
m II
during his fifth annual Farewell Forever tour, said:
> They don't call me 'Ace' for nothing!
You are an arrogant, self titled non entity.
The Wit and Wisdom of Steve Lare, aka dxAce,
Supreme Commander United Michigan Militias
(Updated regularly):
=================================================
I ain't white, but unlike you, I dislike no one.
I said it before, and I say it again... Vicente Fox
is a stinking piece of Mexican shit.
Run along little Canucky dweeb.
Stuff a taco in it, Ramon!
Did I say it was, shit for brains?
I thank the Great Spirit every day for the fact that I'm not white like
you.
They don't call me 'Ace' for nothing!
All of my DX is better than your DX no matter what I do.
After eating the taco's wouldn't they be capable of gassing themelves?
You claim to be 'Cherokee'... I think you're just 'Wannabee'...
How many American lives were affected by the
slant eyed shit throughout the entire war?
Wonder why.... could it be that the Canucky Niggah is timid, afraid...?
Why is it that you queers always seem to **SIGH** a lot? (1)
LOLOLOLOLOLOL... what a damn dumb cunt you are!
Now get your homo ass working on that documentation, boy!
Give it a shot queer boys, I dare ya!
Dumbass Canucks, sure ain't Rolex wearin' respectable folk...!
Cocksuckers such as your self.
Hit the road, 'tard.
Toss 'em all, especially the Canucks!
So, just why is it that you queers always seem to **SIGH** a lot? (2)
Now go suck on some sushi, you little miscreant.
I just asked you to have the cunt send me a letter, boy.
Damn, the Canucky Niggah didn't have a damn thing to say...
So, just why is it that you queers always seem to **SIGH** a lot? (3)
Yes, I am witty, and I am wise!
"I'm so obese I had to get the extra heavy duty plastic blow-up doll"
Let me sum up, you Canucks are assholes!
So, just why is it that you queers always seem to **SIGH** a lot? (4)
Hit the road, drug addled fool.
Shame on CanaDuh for killing thousands of people every day.
Be sure to tell the bitch to send me that letter, faggot!
get your bitch *daughter* to send me a letter
Have the bitch send me the letter!
Well, go tell your other cocksucking countrymen.
Hey, have the bitch send me a letter
Ain't gonna happen, ya got no air farce, ya got no ne vuy, va goy nuthitin?
Have the bitch send me a f00kin letter!
You folk really think ya got balls?
Now run along to wherever it is you little debutantes run off to...
I'll be waiting for that letter from your *daughter*, asshole!
Oh yeah, tell me baby...
Hey, little pussy boy, we spell it "cunt" out here, just like I think I
spelled it originally, boy.
Never touched the skanky,,,
If I don't get that letter, boy, then you and your *daughter* must
both be drunk, eh?
Finally shut you up, eh boy?
Have the bitch send me a letter on whatever letterhead YOU might make up.
Ain't that just speshul! He's got to go find somewun to fake him a lettter.
Have the bitch send me a letter on her firms letterhead, boy.
Great, then get your bitch *daughter* to send me a letter on her firms
letterhead within the next two weeks!
Have your *daughter* draw up a contract, BOY!
Hey, 'Edurado', have your *daughter* get in touch with me, amigo
True, ain't it, little faux Hispanic BOY... (Heavy emphasis on the BOY!)
Guess that shut the little boy up!
Stuff it up your prancing ass, 'Tardo!
You dumb sand niggers (sorry, I categorize ya all this way) need to
understand that you need to get your collective shit together...
I'm LMFAO, since I've busted the f00kin faggot!
You are after all a drug addled 'tard boy who
obviously knows little about the SWL/DX hobby.
Go blow some IBO Cock, and leave the real radio hobbyists alone, OK?
Let the faggot boy prove it!
LMFAO at the f00kin faggot
Yes, I learn more and more with each passing day!
LMFAO at the pathological liar!
Lying 'tard boy, much like the other debutante, malcontent, faux boys
who inhabit the lace we call RRS.
You, on the other hand are nothing more than a sorry little
homosexual 'tard
Liar, liar, pantalunes on fire! (1)
New history will be made when we crush CanaDuh!
Kan you just imagining that, you little faggot Cannucky boy?
Anybody, even Bozo, is worth more than some dumbass, faggot, Canuck!
Get busy, boy!
But you can't prove it, retard boy!
I know you faggots have dreams
Blow it out your ass, you dumbass Canadian! You and the rest of your
dumbass countrymen, and women too!
You'd not be very happy if I returned, little bitch boy!
Go get some IBOCock, 'tard boy, and bring home a taste for yer mama.
If you'd like to call me, I'm here to help you until 0330 GMT at:
616 335-9762
dxAce
Michigan
USA
Go give your boyfriend a blow job!
Talk about misery, you're in f00kin CanaDuh, boy!
Something for your faux Hispanic cock sucking brain to think about, eh?
Or better yet, go get yourself some IBO Cock!
Poor little cocksucker just had it handed to him
Eh? You sum dumass Canucuy bithyboy...
As long as it screws you Canucks, I'm a happy camper!
They are mere asswipes, suitable for flushing.
That's because you're a fucking liar!
Cry me a f00kin river.
Awwwww... the poor whiny dumbass Canuck is back at it again today.
Huh... you be just another stupid white boy outta Cleveland...
I suggest you get together with your "significant other" and bump butt
with each other,
Because I hate White Boy Canucks who suck cock...
Best you shuffle down the alley! That's what your mama wanted!
Crazy Retarded Australian People?
"Even 2 cents is more than a totally worthless Canuck"
Funny how the US Govt. sent me over $50,000 last year
You can preDICK all you want, you fraudulent cock sucking,
pathologically lying old bastard boy!
Hey, dumbfuck Canuck, I was not asked to leave!
I don't use Chink stuff
I went and bought ammo... I still gots it case them tard boys such as
edweena gets stirred up.
And 10,000 rounds isn't a lot.
It was Russian ammo. I don't like the Chinese stuff.
Now where did I put that other case of ammo..
I don't use Chink ammo.
That's not Canuckian, boy!
Kiss my ass, pedant!
I'm LMFAO, Mr. Gay-Lick!
Obfuscate, you little prancer!
LMAO at the 'tard.
Thing is, you 'tards are pretty fixated upon one set of parameters.
That is after all why you are considered to be 'tards!
As always, your head is up your f00kin ass.
You fuckin' Liberal asswipes are always ready to give somebodys else's
goodies away...
And, hopefully, my dumbass cousin in Mill Valley will leave me her
Corvette.
Obviously, you leep your head up your f00kin ass all day long.
I don't 'fear' homos, oh faux one!
Liar, liar, pantalunes on fire! (2)
Apparently you are the 'bendover boy'....
Do you spit or swallow?
Oh, I certainly have, time after time.
At least I went farther than you!
Good lubricant for you and the boys?
It's what dxAce uses!
that's good enough for me!
One can never slide the BS by dxAce
Not as well as you, fudge pack.
Go for it, dumbass!
Oh come on... it's Fall forward and Spring back. Everyone knows that!
Hit the road, drug addled fool.
Hey, I love kickin' gay-lick ass!
Pretty much what I indicated to you a while back, you f00kin prancer.
The only thing you know about short wave is that that is what your
mother gave you when she sent your f00kin ass packin' outta Cleveland.
Screw the drug addled retards.
Nah, I only attack the messenger when he/she/it is
obviously drug addled.
So, beat the rush and get the hell off of RRS, you f00kin retard.
Well, in you, we have a drug addled retard in our midst.
Get over it, you fake Hispanic piece of excrement.
And when you do confront HD, you'll have Cocksucker Dave and
The Prancer Boys to thank for it.
Damn... I'm of mixed race ancestry myself, what ever should I do?
Next time we come over the pond once again to save your sorry ass's
we'll have to dismantle that stuff.
Heck, I bought 1000 shares of FSEAX the other day.
Don't do business with the Huntington Investment Company,
in particular a fellow named Joseph Klein.
Not at all, we are both Miami Indians. ya got a problem with that, boy?
Ya right, suck my dick...
Believe it, it's like a dream to be with you again...
Then hit the road, you drug addled retard.
Just like you wish that you worked for me, retard!
Proven time and time again, fudge pack.
Get it, retard?
Dey done unnerstannn that us nateev boyyys R real Mericans!
I sure he is.
Insert your Gay-Lick reply here, boy:
And yet another Liberal rant
Sorry, I'm not a racist like you, Edweenie...
Nah, he was fake little cock sucker like you!
Your pathological lying is an offense to me, and more than likely an
offense to God as well.
No medications here, cock sucker boy..
Stuff a watermelon up it
But that stuff isn't what dxAce uses!
Come on now, you being a nice Liberal, Carbon Footprint, Al Gore, Cock
Sucking kinda Canuck Bastard..
I won R plantation up nord, dat dem dum ass Canuckys be oween us, ya be
'standin me?
CanaDuh is stupidity!
Stupid little pussy faggot!
Liar, liar, pantalunes on fire! (3)
Mr. Edweenie, the forces of Good are gonna come visit your sorry fake
Hispanic White Boy Ass if you keep it up!
Pay attention, cock sucker...
LMFAO as I sit and look at my royalty cheques...
You've done this before, cock sucker...
LMFAO at yet another dumb friggin Canuck..
I know it may be hard, but as you withdraw, it will shrink away..
Oh damn, I guess we pissed another wanker off, Cuz..
I get my ride be fixed, I be cruisin to be givin ya da shake, yu be
knowin, eh?
Try again, shithead.....
Dem Canucky boyz are dumaz rasissts..
We gone be sen u to sumplac bad boy... u be so bad weben the reel
Canuckys won wan u.
Fookin bustards! Like Edweenie!
Best you wake up soon... fookin retard leetle beetch..
Fookin 'retard.
It is then my patriotic friend, you must reach in the closet,
place your hands upon the weapon, and blow the cock sucking,
bean blower back into Mary's arms....
Indeed, I'm now at WAR with Canuckistan..
May the Great Spirit help the hapless bastards.
Actually VA facilities are quite good, but if you Canucky niggahs poke
around one might find a lot of things wrong.
At any rate, I'd bet it beats the Canucky Third World state of care...
CanaDuh sucks...
Wanna go to war, shit head?
Think you might win? Think you got a chance?
If you don't... I'd keep my fookin Canucky mouth shut, boy...
Meanwhile, I plan for the Spring campaign, looking forward to the
Blind River Massacre.
I collect stamps!
*********************************************
dxAce
m II wrote:
> dxAcehole, pathological liar, racist and common drunk,
> during his fifth annual Farewell Forever tour, said:
>
> > They don't call me 'Ace' for nothing!
>
> You are an arrogant, self titled non entity.
Yeah, and you're just another dumbass Canuck!
Go blow 'Eduardo', boy.
Pete KE9OA
that I will have to change the 150pF shunt cap at the filter input to 220pF,
to make the filter symmetrical. This is for the R8.
As far as the R7, the 25V power supply line for the tune voltage was only
7V. This is the reason the receiver only locks on the low ranges. Unless the
power supply board has gone through some sort of revision, somebody replaced
the 78L24 regulator with an LM317Z. The 78L24 is a low current 24V positive
regulator, while the 317 is an adjustable regulator. Totally different
pin-out from the original, and it would never work in this circuit.
Basically, there is a multivibrator circuit that provides 35VAC. This
voltage is full-wave rectified with a bridge consisting of r 1N4148s,
filtered, and applied to the 24V regulator.
I should be able to get it running, once I get the correct part.
Pete
"dxAce" <dx...@milestones.com> wrote in message
news:47C6FB8C...@milestones.com...
Pete KE9OA
ranges. No difference in sensitivity over the whole tuning range. 10uV RF
input gives S6 meter reading, indicating that there is no MW attenuator in
the non-European version. Good news.............not I don't have to tear
into it until I figure out the preamp enable mod for the LW/MW ranges.
Pete
"Pete KE9OA" <p.gi...@comcast.net> wrote in message
news:N6udneS41br2alva...@comcast.com...
dxAce
Pete KE9OA wrote:
> I checked the sensitivity of the R8 at the MW band edges vs the adjacent
> ranges. No difference in sensitivity over the whole tuning range. 10uV RF
> input gives S6 meter reading, indicating that there is no MW attenuator in
> the non-European version. Good news.............not I don't have to tear
> into it until I figure out the preamp enable mod for the LW/MW ranges.
Let us know.
Pete KE9OA
Drakefan
Does your R8 have an optical tuning encoder? I've been thinking about
replacing the mechanical encoder on the 'B' model with an optical type,
maybe a Bourns.
Thanks
dave
> Thanks Steve............I appreciate that. Years ago, when I was living in
Atlas, Atlas...
Pete KE9OA
FINALLY been solved. There is indeed a MW attenuator that can be
implemented, by moving at least one jumper on one of the headers at the
input of the MW filter section.
According to the schematic, normal operation has the attenuator disabled.
Good news for me!
I am still working on the preamp enable mod, but I haven't found anything
yet. There is a way to enable the preamp by providing a jumper between the
collector and emitter of Q106, but I wouldn't go that way myself, since the
preamplifier would always be enabled. I am still looking for an inhibit
line...........
Pete
"Pete KE9OA" <p.gi...@comcast.net> wrote in message
news:6ZSdnVXc0q_zplva...@comcast.com...
dxAce
Pete KE9OA wrote:
> Looking at the schematic of the front end, the MW attenuator mystery has
> FINALLY been solved. There is indeed a MW attenuator that can be
> implemented, by moving at least one jumper on one of the headers at the
> input of the MW filter section.
I'm not sure just what you're trying to do Pete, but the MW attenuator is
accessible on the R8 directly from the front panel. 10 dB I believe.
Pete KE9OA
encoder, first of all, you would need to order a Quadrature optical
encoder.............32 pulses per revolution is fine.
Next, you would need to remove the +5V pullup resistors from the encoder
lines, since an optical encoder provides +5V pulses. Once you install the
encoder, connect +5V, ground, and channel A and channel B outputs to the
tuning lines that were originally connected to the mechanical encoder.
If your tuning is reversed, meaning that when you rotate the tuning knob
clockwise the frequency decreases instead of increased, you only need to
interchange the channel A and B outputs.
The encoder should run you about 30 to 40 dollars vs the 4 or 5 dollars of
the mechanical encoder.
One thing I notice with my R8.............when tuning, I can hear some
pulses in the speaker output. The remedy for this is to wrap the tuning
lines in copper tape and ground the tape. Sometimes you have to be careful
here, because the extra capacitance incurred because of the copper shield
can cause too long of a time constant, rounding off the square wave pulses
ot the encoder output. I ran into this problem with my DDS based
synthesizer, and ended up using lower value pullup resistors at the uP
inputs.......this supplied more current to the tune lines, thus, reducing
the RC time constant. Worked like a champ!
Pete
"Drakefan" <Drak...@bluesky.net> wrote in message
news:tqKxj.13404$o23.6987@trndny09...
Pete KE9OA
implemented, but moving those jumpers that are at the input of the MW filter
section. Similar to the implementation that is used in the Kenwood TS-570.
Since the schematic shows normal operation with this thing disabled, I am
thinking that this option is intended for European markets. The only spur
that I see on the MW band in my location is a 3rd order product at 500kHz
from WGN 720 mixing with WKRS 1220.
A preselector eliminates this spur. I see why some of the manufacturers
chose 0 to1MHz for the LW range and 1 to 2MHz for the next range. Still, I
like to see a low-pass filter at 500kHz for the LW band.
It definitely is a nice receiver.......using a Wavetek Model 2407 rf
generator, sensitivity was flat across the whole tuning range.
They are using a Mini-Circuits SBL-3 as the 1st mixer. This mixer has an
operating range of 40kHz to 200MHz, with an SSB conversion loss of only
4.75dB or so. Since later iterations of the R8 series receiver improved the
IP3 from the original +5dBm to +20dBm, I am thinking that they must have
switched to either an SRA-3H or and SRA-3MH. These mixers have an LO
injection level of +20dBm and +13dBm respectively. Operation of these later
iterations should be similar to the Drake R7.
I am glad that I picked this one up.
Pete
"dxAce" <dx...@milestones.com> wrote in message
news:47C80AB8...@milestones.com...
Pete KE9OA
required a higher LO injection level, they would have also needed to
increast the RF output of the 1st injection oscillator to provide the
required level. This is not a drop-in replacement!
Pete
"Pete KE9OA" <p.gi...@comcast.net> wrote in message
news:472dnXKw5empiVXa...@comcast.com...
Dale Parfitt
"Pete KE9OA" <p.gi...@comcast.net> wrote in message
news:6ZSdnVXc0q_zplva...@comcast.com...
>I may be picking up one of these things tomorrow. Looking at the input
>bandpass filter schematic, I notice a T type of attenuator that consists of
>two 270 ohm series resistors, with a 330 ohm shunt resistor on the MW
>filter section.
> Am I dreaming, or did Drake really dumb down the design with a full time
> attenuator on the MW band? If this is the case, it looks like I have yet
> another project.
>
> Pete
Where do you think Icom got the idea from??
Dale W4OP
Pete KE9OA
and if definitely needs a preamp in order to have good sensitivity. This is
where the R8 A and B has an advantage since you can enable the preamp on all
ranges.
With a long wire, or an active loop antenna, it is pretty good.
Pete
"Dale Parfitt" <par...@verizon.net> wrote in message
news:dJUxj.414$C1.92@trnddc07...