Call sign: K5jxh  
           My  SB-300  just added to my relic sub-station
Circa 1968-1974 sold new.(SB line)(dates?)
Heath's last tube rig? 1983. (
see ham pages, of sales catalog  1969)
         Modifications & et cetera
I journalize my projects as I do the work and wait, and wait for parts to arrive.(done)
My rig.

First let me say , I just love this receiver, it is one hot potato,  (very very sensitive, front end  that gets DX real good , far better than my expensive rigs) Do not let TUBES (De Forest Audion's) scare you. (Joking Hollow State Electronics)
The 6BZ6 RF front end is very good. (even now) One hack is to change the 150 ohm cathode resistor to about 56 ohms (near) for DX work. (use the RF gain to prevent blocking issues, on local strong stations.)
This tube BZ6 can have a transconductance of 8k to 10k uMho's.(microsiemens) or simply High gain, a low element Capacitance ,RF amp tube. (study Mr. Van der Bijl )
The one thing that can be hard is finding all the missing crystals

It came in a cardboard box, and as the lid opened, the smell of mouse pee +  tabacco smoke, knocked me to the floor, 3 days of  near 3 quarts of pure alcohol later (flushing endlessly) It is now smell free, and nice inside.
After cleaning it with pure alcohol.  or at least ( label states 99% and 1% water , not the kind called Rubbing, some have sheep oil called Lanolin or other nasty oils there, Walmart Alcohol was good to go, in first aid or in the paint department)
Never use other  solvents, (no  acetone, no Lacquer thinners that damage any class of plastics, and no water for sure garden hose flush downs as seen on YOUTUBE)
Try to get no cleaners  inside the transformers or coils, nor inside the VFO tuner (I just brush the Alcohol on gently laid side to side repeat, let chassis tilt a bit, out doors, and let the junk drift in to a bucket or dish pan for recycling it.) ( me with gas mask from WW2)

Photo1: Clean and tuned.  I made a printed label to make tuning more easy, on the coil box. (Het OSC, RF amp , ANT) seen here. " I used the manual photos to make print outs here, scaled carefully"
1972?
Factory built Heathkit(tm) are best, but DIY are ok of you inspect all soldering joints and re-solder all that look bad, cold joints loose or just ugly  bad, as you will find. 

The folks that bad mouth Heathkits for DIY bad work is sad to hear, and dead wrong. (and years of bad service or exposure to bad elements (basement flood in 1980?)

Feet screws too long danger:
The two bottom feet screws, seen here ( left side really) as factory NutSerts® the one on the left cuts in to phone jack wires, but the right  one below, cuts in to the audio transformer casing (that be nasty bad)
I used blank raw PCB fiberglass (FR4) board material to built and installed  2 blocking plates in those 2 places.  using those 2  factory corner, counter sunk #6 screws seen there.
I do not want to wreck my old transformer seen below right, ever. (even if I make  mistake, grabbing screws)
Click bottom photo to ZOOM.

My 1st tube receiver after 45 years, and does it ever work good. ( very very sensitive it is)  (from 1958 to 1968 I had many many SWL receivers, SX-115   Hallicrafters receiver, and some REGens 3tube wonderss that were junk.
I even had  Knightkit Short wave.. (I traded many times with friends just for variety sake even a
STAR ROAMER and a Lafayette something, I forget what now)

Buying anything like this is an  act of pure raw faith ,that  those wafer switches are good and not damaged, as many are.

Red wire above  is Teflon 150v rated, and most of the bias wire yellow are all Teflon now, those  2 huge resistors, get hot, and  burned the too  near by wires badly, this was corrected with Teflon wire and sleeving (red)
When reworking COAX cables, make very sure the grounds are attached as the Heath manual shows you to do,  1 end grounded or both, do not guess !, or you will get a  ground loop, and you never want that to happen.


The lists of checks and mods.
  • Clean it up the front and chassis , if need be. (find any weak tubes, if any at all, any damage or burned parts, etc. [you will find something on any thing 50 + years old..!])
  • Repair all DIY bad solder joints now.
  • Make sure all screws and nuts and all things that are grounded are tight.
  • New wiring , due to heat damage, cured. (Teflon wire is a forever cure)
  • Removed the VFO tuner, and find that the grease on that magic coupling device on the shaft, is more like glue or cement, clean all that off and free it up first thing you do  and re-lube it. (I used high temp car brake grease)
  • AC power mod ,  and fix all bad Grounds !
  • Tune (align) it up, per the manual.  (using my scope, and home made DDS signal generator and pads)
  • It's now running like new.
  • Added a 1st IF Pan-Adapter jack (for future experiments)
  • Add my external DSP audio filter.(it is not all that impressive)
  • Make it work with my SB401. (pair mated)
What does a stock VFO look like inside ? here is the  tricky-sticky? coupling device, it is on the right side seen here, I did not need to take apart the tuner, just clean all the gunk off of this staged coupling.(they love to glue together and fail)
The tuner is never DIY, all come factory wired, so will be only issues with grease gone wild. (SB line is TRW tuner factory made at TRW co.)
See the staged coupling device see to far right. (must be cleaned)

Just for fun view here, what is inside that tuner. (no plastic gears ,nice)  note the spring loaded anti-lash gear.
The beauty of the aluminum chassis are that it does not rust, or corrode (aka. Oxidization ) if kept indoors, unlike steel  or even copper clad steel. (steel is the cheapest, and injected plastic today even more cheaper)


PANADAPTER: (all theory now here...,  how to add the PAN jack to the rear of this RIG, is here. )
A panadaptor is just  cheap, spectrum analyzer,  the cheapest (not poor) are just for watching what is in the IF strip. (1st mixer out)
Another way to get this same or better effect is with any REAL SDR radio.  I only offer the below as way to make your own, Pan port.
With such a device, one can see the whole band at once,  something that must be seen to appreciated .
This a Gimmick jack , a triangle symbol.(a BNC jack) Back in the dark ages of radio 2pF caps are not found or rare so they used 2 wires twisted together and named it a gimmick.
Today we can buy  a 200v rated 2pf cap.  2E-12 Farads.
Ouch, the wire here V2 pin 5 to T2-p3 is just a 1" PCB trace,  so use a modern 2pF cap here, if  you want to make  PAN jack.
The bad idea of this is the cap will detune the T2 tuning

See full schematic here. and options for PAN.

 


Panadapter information found, and is a  near match to the  HW101 (cheaper hot water 101, Heathkit):
This shows you how to do most tube receivers. see the links below for details. (super good information)
Mr. Ranickel (THANKS !)


Other modifications  for Digital tuning? Upgrade?
VFO (upgrades) Using modern DDS VFO's. 
The digital VFO mod, not hacking up the rig internally, just a unplug the internal VFO and extend it to a rear spare jack. (using  DDS based new VFO)  Most seller of said boxes, went off line.... sadly....
The DDS I going to use and review is here.  (sold on fleabay, this unit is  a clone of the this German unit) (nice) using magical Google web page translator, nets you this page.
The above German page has the schematic and the PIC processor hex code too,  (thank you, author ! VU3CNS)
The key trick here is a tuner that can be set to your Heterodyne offset frequency of the I.F. strip (sum and differences, as the case applies,)
These VFO mod's today are not active, nobody wants a TUBE RX at all,  nor wants to mod one ,or does not want to modify a classic old Receiver, wanting  it kept 100% original. (The AC mod. is needed )


Audio: (mods?  that is not really mod but an external added option)
The, Audio noise filter mod using  a DSP box outside to do that, some are really very good.
Sold by many but this one is best, (IMO) I like the MFJ-784B (used) the average used price  is $69 (12 samples data )
MSRP is super high.$300 delivered? more that the radio. wow.(my guess is its $25 in parts and $250 in NRE+profit)
I tried this filter  box, MFJ and was not impressed at all.


My patch cables. ( to join up the SB401)


Just about any speaker works , and most Home Theater speakers too, seen used for $5 at GoodWill (tm) stores. (no need at all for HIFI grade speakers, just 6"  in a box will do, any box, any speaker) or use phones.


 The long story. (My journal)
Now the nitty gritty details, of what I did.
I got this radio, delivered, now.  "When Life deals you lemons, make lemonade"?
It looked like a smoker used it and smoked 3 packs a day in his shack? (doors closed, etc)
And full of mouse pee,  Smoke tar and pee, what combo... LOL. (with gas mask fitted I...)
The whole radio was coated with this nasty patina of brown slime. (doing some kind of biological transformation of bacteria gone wild)
Not dissuaded at all , it's an  old rig and many are like this, what matters to me is the band switches are good, as are all coils and transformers , all else to me, is a cake walk/fix/buy/spares.
I cleaned the switches with pro grade , contact cleaner (spray from mouser). They look great,  I don't ever worry black silver tarnish, it's NORMAL:.
I would never clean any radio with water, as is seen by folks on Youtube.com or other ham forums,   wow, water and electronics... (sorry this is not SMD =Surface mounted devices on  PCBs and water soluble flux era.)
The radio uses solvent only Rosin fux, and Alcohol is best or expensive ROSIN flux remover. (sold at Mouser.com)
Never get water inside any transformers or coils  ever nor on POT's, and never oil a POT ever deep inside , shafts sure,, just use Pot cleaner.. Nor in that large metal tuner.(VFO/LMO)

Then with that done ,  I used my near pure 99% alcohol , in my spray  bottle, and then cleaned every inch of the radio, took, me 4 hours.  (not my first) and 1 full quart of Alcohol. (brush on , let it drain off outdoors)
If I'd known the radio stinks, bam,  I'd have bid 1/2 what I paid....or not at all....  (well, can't take money to heaven so.... no problems here.) Yah's pays yee's money and yee takes yahs chances.....
Best of all buy used rigs at a HAM fest, and sniff first. (yuk)

 
The outer shell perforated  case was cleaned up easy with AJAX cleaner. (scouring powder) and water, it's just a case and looks new cleaned, the base is Aluminum not rusty steel.
I then inspected every inch of wire, found 2 shorts, and broken shields on many internal coax lines.
The builder had trouble with coax, it seems. (details matter on coax, like grounding 1 end  or both ends matters and depends on the circuit applications , audio, RF or controls,etc.)
2 filter cap.'s were wrong in the power supply sections.
I converted all 47 lamps (x3) to LED (bright white,) (only 5minute to reverse that, if need be, so is not really a mod)

I fired it up and she works on 1 band 7mhz only, found the HET tuning coils all set wrong, every one on the wrong side (of the tuned hump) , per the books warnings. (Heaths) (fast hump and slow hump, use the slow side)
The guy that built it may not have understood what the book said on this. (easy if not a RF radio head)
In fact, tube  V4 the HET oscillator is dead, I used my scope on the RCA HET. jack on the rear, super easy checks, this way, and she be DEAD,  on all bands but one.
I tuned the slugs for the other bands to the slow side of the peak and BAM, rock solid HET on all bands. (every time,  every turn of the dials)
HET= Heterodyning (sum and difference rules) it is a mixer of RF signals.  (and most be setup correctly  or is worthless)

The radio is 50 years old today, and will need a full tune up, others telling you not, are full of beans. If you do not want to tune radio (calibration) get and SDR rig.
I did a full tune up with my cheap DDS signal generator and my scope and she works great now.. solid as a ROCK.  (I now have  Wavetek 3006 signal generator, restored, and not easy to do...)
I tuned the radio (alignment /calibrations) per the below SB300  manual. PDF.
I can hear other hams, on 40 and 20 meters all over the USA. (world) now.

I like seeing old rigs, operate  and work.
I am getting to love this rig.
 The easy tuning and the clarity of voices, in SSB are great !  (it's pure analog, no DSP chip (digital signal processors)  , translated  audio,  real audio)  Buy one and try it.... (a blast from the past)
The warm glow at night , even heats ths shack a bit.  I like to call it my full metal radio.  Just don't drool into the Plate DC power lines. hihi


AC power line mod: ( I consider this , non optional,  Safety first)  Ralph Nader would call this UNSAFE AT ANY FREQUENCY?
Now my safety up grade, so nobody ever  gets hit with 160vdc touching the chassis. (never get a hot chassis)! nor your kids, or wife, or ?  I can tell you once bitten , twice shy. ( my SB200 linear amp is lethal , no 2nd changes...)
The stock radio is unsafe. ( back in 1960's what's a safety ground?) 15minutes cutting, and 15min soldering. done.  (0.78 x 1.05" square hole)  Those old slotted screws are so RETRO ! (and really kinda cool)
 See my added ground stud and SST washers, at large white arrow.
I can tell you that you never want the chassis ever to float up to 160vdc with full Power supply current behind it. (It will not make your day) (one could use GFI to make this safe but why trust your life to GFI? , it is for a backup to real grounds failed)

The brown PCB patina below  is very 48 years old flux, remainders, after the clean ,  the dust seen is  gone using shop air.
The 2 maroon factory ceramic caps , replaced  now, are now changed to Yellow to UL spec. Cap;'s.*(as  seen in my SB401 pages)
The 2 caps are RF decoupling caps, both entering the Radio or exiting Radio.  The CORCOM filte even has common mode rejection transformer inside that is the bee's Knees best of best way to go, as see today on ALL GEAR.
The C1 and C2 caps need to be replaced with CLASS X1/Y2 rated UL safety cap.'s, rated for not shorting out,  sitting on the line power 24/7 .   The correct caps are sold at  Mouser, cheap.
Cap. maker  Vishay #
VY2103M63Y5US63L7 
The old caps are not safe they can short while you are asleep in bed, at 2A.M. and shoots white hot sparks out  the bottom of the chassis, starting a fire.
The new caps can not do that. (by law, UL , etc.. world wide rules.)


These are DUAL rated caps.
A better upgrade to just a jack here is a real CorCom filter. (TE.com) 6EEJ1 or ~J8 seen here. (an industry standard today)  (this Corcoms keep RF from sneaking into or out  of the Receiver,  on the AC line)
I added a HDuty ground stud, seen here, and with star washers ! The black hot wire is Teflon and is fused first.  The y2 rated caps are designed to never short, but if they did my power strip fuse blows. (pops)
The corcom is even better, it keeps RF from going out  the receivers, AC line wires and from coming in that way.(always a good thing that)
The better choice is here, but a tight fit on some rigs.
I did not have a real CorCom in my junk box today , when I did this job. So used the cheap snap-in jack.


The 2 PCBs use the hope and prayer method of grounding (see sandpaper steps in the manual, try not to laugh) a near hopeless idea if ever there was. (what were they thinking? )
Let me guess 50 years latter, omg, it's oxidized now, so after cleaning it , this will not fail (corrode) in 50 years,  HIHI !
I then added 2 new, ground lugs (star washer type) to both PCB screw mounts,  1 for each card, then used SolderWick® braid wire, to solder both ends.  This makes a solid ground,  (you will not be sorry you did this , grin !)
Seen here, the ground mod.  Like 5 min work and no more  Goofy, grounds. (twist the chassis running, see if things go dead,  a test)
The PCB (printed circuit boards, Not toxic transformer oil) have ground traces, that must be perfectly BONDED to the case,  make sure they all are, do not trust the trace to just lay agaist the chassis as seen in upper corner here.
Oop's is DIY guy did not solder this Cap,lead at all, oops.
Later I replaced all the HV DC power wires with Teflon® wire. Mil grade. (red wires,  see the first one on lower far left here,  (the stock wire, were super bad, and I didn't want HV DC hitting the chassis.(ever)
See oop's that is a cap not soldered.


Ok my last chassis mod.   (most folks will skip this, I did it only for future experiements)
A nicer antenna jack that will not fall out, and a new VFO in jack for my DDS VFO and the new Panadapter jack.  (to be developed, last) No drilling needed, they fit prefect. 1/2" nuts (+star lock washer)on back,.
I'm using the original 2  Jacks marked spare on the rear. For my VFO tuner and my Panadapter.

Those slotted screws,  are really old relics. ( no factory can build fast with any slotted screws)

 






NEW CAP TIME:  (Mouser.com time)  (CDE stopped making 3 way caps long ago in this HV spec)
Home grown cap (3 sections, old cap can leaked  , acid badly)
Total cost to do below $3 USD  (not $50 sold by scalpers ) and better, Nichicons and low ESR spec. (non corrosive RTV used !) Note only the CAP is modified not the RIG.

Peak  Ripple measurements after all new filter caps. (there are no regulators here, only brute force caps, so ripple is normal)  (48 years and a 5:1 reduction in size) But I kept  the base forum factor.
One could put the CAP shell back on, then wrap the seam with aluminum tape (the kind with sticky glue used in HVAC vents ) To get a more Relic look, but I'm ok with mine like this.

Bad titty day: (Heathkit #266-74 , It broke)
(if the tuner gets out of time, with the dial and it hits the tuner stops, it breaks) "My bad" I knew better just spazzed out. (a 1960s term)
With front off, the last of the filth is gone... hoorah.  The LED mod, makes for cool dial back light , blue/white !
The DIAL issues, most are bad, with a large amount of cracks inside, or worse. EPOXY is the cure.
I remove the dial, and back flood it with Epoxy.
This side that is not with the spiral grooves is back filled,This ends all possible further cracking.
The SB line of Rigs, all use the same DIAL  (analog, radios not the SB104 digital) nor do the HW series fit here.    <<< stated here to find a spare Dial more easy on Fleabay.

$12 for a new titty, dang. (next time? I  machine a new one from Delrin plastic?)  Having a dead , slide rule scale on my radio made me want to fix it....  In fact, my tuner works perfect. (stock)
The titty button (boss) device, I think is Nylon, (common plastic of the 1970s)  and near impossible to glue it.
Brain storm?:  ( or  drill and tap it out to say 4-40 size or smaller screw 2-56 and then put a filed down headless screw there,...(not tired by me) {my local RC radio /car Hobby shop sells screws this tiny}

The dial must be fitted with great care, so that there is no stress on the titty guide.  
The tuner slides in and out at its base this is a calibration too, the dial knob, is a greaseless slotted wheel that meshes with the plastic/steel knifeedge dial rim, (steel knife edge) and must be calibrated too.
So that it just touches,and not crush the dial or stress it at all.
This is the most hard part of the radio to get right, this dial and the knob pinch roller.
And the Epoxy flooding trick.

In many cases owners use WD40 (from H3LL) on the coupling, and it then gets on the dial roller and slips, a hopeless place to be, please do not use oil here.
Use high temp grease only on on the coupling inside and ever on the outer dial roller knob wedge rim.

Theory of operations that tuning DIAL:
 (the SB401 manual Dial only pages annotated for pitfalls and details...)

The SB301 dial only pages are here. (high Res. and clean , printable)

The operator does not turn the (LMO)tuner only the DIAL does. (a big round dial seen in above photo right) the operator turns this funky little knob with pinch edge roller on the end.
There are 4+ adjustments , making this super hard to do.
RTM the book tells you to lay a straight edge on the case and with the tuner base bolts loose set an exact distance, first. (and not canted !)
Then then bottom the dail and set the gap, per the above link. The VFO is no forever mounted and set, and tight.
Set the DIAL set screw such that the DIAL does not bind on the titty button. it must glide not bind.
Make sure the DIAL is timed right (rotation wise with its set screw)  or the titty button will bottom out  and break
Lets it the human funky know wedge wheel.  
  • Do not oil the tuner or the shafts of any kind here, use grease in the tuner coupling only. (I use autostore $1 packets of brake grease its a stiff very high temp. grease and will not migrate ever, by design)
  • Do not use WD40 in any radio made (or other like Pen.oils), it's oil based. and loves to go places never good. (migrates)
  • The main knob outer pinch edge must never be greased or oil or it will slip hopelessly.(same is true of dial inner steel ring, I call this the knife edge ring)
  • The shaft on that human knob can be very lightly greased as the manual links above state, but only if you are sure it can't migrate up to the pinch roller edges. (ever)
  • The knob moves up and down in a adjustment slot this is the LAST step, so adjust it so the rim (pincher) just lands on the steel dial knife edge ring, so it just barely does not slip, if set too tight the dial loves to crack.
  • That knob device, must be inserted in the up position first then lowered to the knife edge if not done right and allowed to fall behind the knife edge it jams there, and fails.
  • That is it on this very tricky device.  (once mastered this skill it works like champ !) My 2 rigs both tune just like new. (I may try to do the screw fix (titty fix) later) and show it here.(for  spare)
 
Do not put grease where grease does not belong.  (I think the new in box DIY kit came with special Silicon grease that does not migrate)
The last step is sliding the knob dial bushing down until the pinch roller just touches the knife edge, lightly, (it is about only ounces of pressure here, very little) the tighten the brass bushing nut.

Examples:






I have now done 2 , epoxy floods to 2 (SB) dials, and after 2 years, all is good.



RIPPLE (not cheap wine) but  Power supply Ripple. (after new caps) Ripple is  DC power supply spec,  (all supplies have it, linear or SMPS, what matters it is not out of spec. (spec. means factory specifications)
If out of spec, caps are bad.  (check ESR on suspect caps)

Real Data: "Mine"
Marked    ,    DMM measured Volts   and  ripple:(peak) measured  with a 100 MHz scope(DSO).  In operate mode, antenna grounded. 
+150v (142v) measures 160vdc  @ 50mV p @C228
+148v measure 155vdc  @ 200mV p
+120v measure 142vdc. @ 20mV p  60Hz (very good)
-60v bias/mute    -93vdc @100mV p  at C226   (mute pin at c239 ripple  is 2 mV)  Ripple on this wire varies, it is used to bias many tubes, and the ripple there is almost zero. It is also the RF GAIN bias.
I have the most slightest speaker 60Hz hum... very tiny, not objectionable to me... but... curious as a cat... I ...
I isolated  this noise, using these methods: (classic ways, all)  the Electrolytic filters are new, but I let the chips fall where they may...  "what chips?" cow chips?"
  • Turned the AF gain knob to zero, hum gone now, so hum is before this point (before audio amp's)., which is V9a.
  • V9a is the Product Detector triode, I grounded pin 6 grid pin,  still humming. (V9a, is source) (so is not source feed to V9a)
  • V9a I then add 220uf CAP to DC supply to top of R221 100k resistor, high side , and no change in hum. (3x normal capacitance now)
  • V9a , lastly I ground out the C231 green wire, this is V9A output, and the hum ends. (so all noise is from the confines of V9a,, 6AS11, Compactron !)
  • Conclusion,  V9a is the culprit,  filament/Kathode hum is suspected, and my spare tube hums too. ( pin 12 is at ground, so I jumped this pin to chassis ground, no improvement) So I deem this Normal. (the tube is a relic and hard to find)
  • My speaker wires are connected  to my external DSP audio filter (MFJ) so , all hum is canceled there any way. (super easy work for any DSP filter,with repetitive noise line HUM)
"K" element is Cathode , since the days of De Forest. 1903
See my super good schematic here,(HR + color)

Bugs:
Found V3, capacitor C17 open, not soldered back in 1968 , bam , the weak Radio now works like new, it's red hot sensitive and selective.  Love it.
Oops, my top scale tuner slide rule, failed due to the plastic titty broke off,  twinky guide part (Heath#266-74) in the main rear dial , guider (coarse) broke,  lasted 48 years,  wow.
Fixed many bad grounds and even tube socket pins that were not soldered right, and loose at PCB.  (kits are like that)
I wiggle all parts in the radio with my plastic rod, to listen for , noise in the speaker,  powered up. I can find many problems using this trick as well as wiggling each tube to see it it makes noise (gloves on , yes)
Added a hard case ground to both MAIN PCB's.  (works like magic this on old gear)  Heath and grounds are always suspect, but easy to fix. 10 minute work. (with parts in hand)
PCB = Printed Circuit Boards. (not toxic poison  transformer oils)


Carbon 14 dating Radio's (rigs) The question how old is this beast?
Even the WIKI fails here.
The tubes and most capacitors are all date coded, but tubes get changed out, but if they are all marked 1969,  It is a good sign of 1969. (or most are) Btw, most tubes are easy to find even today. (and prices falling now)
The Caps, can be older,  the makers buy parts in large lots, and use them for up to a 3 year run (typical of the era, no back then JIT, Just in time methods then) (I worked in Telcom factory 1975)
If you find just one IC on the RIG, the date codes are the same,  7319 = 1974 work week 19 made) and the RIG may have 3 year old chips, used, built new. (a fact) and chip maker far later went to secret date code, that we have learned the hard way to decode.
Example #1 Carbon foot print 1.  (back then WV = working volts) wow not made in China.... the glory days of Radio. Aerovox 1964 SB200
Aerovox founded in 1922 as Radiola Wireless Corporation is now.
In June 1973, AVX became the parent company pf Aerovox. (the still make HVAC cap's ) made work week 04(January)
 Be aware they used real dates, and Julian dates and omg anti-Julian dates back then, my company had 10 months in Calendar year, (Philips semi now NXP)
Even tubes went to encrypted dates (1980s?),as did chips and most parts made (lawyers caused this)  but we can decode RCA easy and others. (lawsuits of date codes, unending caused that... bs)

Remember when the USA made things?
I replaced mine (above)in the SB200 for  fear of these 6x  cap shorting and wrecking an  impossible to find 2kv transfomer.(sorry that was digression but the above cap is super old and P/n clear to read.)


BOOKS, files and best links.
Full manual, with search able content (OCR'd)  Optical character recognition,  I ran that on the file and saved it. 

I glued the 3 schematics together with Paint  Shop Pro  x9 ®.   All in 1 page and with secrets shown.

The insides can look this good.

The best LPF tuning page is here (a java modeling engine) Gold plated GOOD ! Thanks !

See my super good schematic here,(H-Res + color)

I try to do 200-DPI resolution or better scans. (my Desktop screen is 112 DPI dots per inch ) In truth the JPG compression settings are more important on photos, 10% is better that 20.


A Flash back to the  Winter  of 1969    Heathkit Catalog.


Jargon,?
Besides Ham Jive (like hihi for LOL and 72's or Roger Willco)
Fleabay.com  (means your favorite flea market web site of your choice)
OMG = Oh my golly even OMG gee wiz?
(back in 1965 uuf =  pf , as did mmf, micro micro farads, as joke then we said get a 2 mickey mouse cap.) Jargon changes in time. pF is said today get a 2 puff cap. in there. 2E-12 (a seen in your Physics class?)
OCR (Optical Character Recognition )the magic software that converts photos of text to real text and then indexes them (PDF),
LMO = Local Master Oscillator. (VFO is variable Freq. Osc.) I most cases LMO is inside the gear, and VFO is outside in box, upgrading precision and drift specs.(or even using Digital DDS  but watch out for phase noise)
PCB = Printed Circuit Boards (no Dioxins , not fire retarding tranfomer oil.)
Mod.'s = Modifications.
RIG =  Gear = equipment or even a system of Gear. Noun #6.
KIT = A new and popular word, used now by the miliatry, they grab there rigs, box them up with cables, etc and it is now a portable KIT.  Did you kit up the SAT rig,  yes/no?  Ok load it and lets go.

The above is just my experience and only my opinions, what your rigs condition will be in , nobody can guess.
This is only a Journal, (but I share all mine, many Hams do this, it's a  tradition now.)


version 2.  11-20-2016     If you need help ask, I  have endless time here (well at 70yo sure... ) My 3' rd ever tube rig was here (USNavy)URC9's (with super early DDS tuning !)