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Showing posts with label Drake 2B. Show all posts
Showing posts with label Drake 2B. Show all posts

Friday, December 13, 2019

Crystals -- Old and New and World War Two


I was watching Greg Charvat's great video about the WWII ARC-5 receiver yesterday. Greg admonished all of us to preserve any WWII gear we might have in our shacks.  Just one day earlier I had found the crystal pictured above in my junk box.   There is some old stuff floating around in here! I will preserve this one. 

Speaking of crystals,  Walter KA4KXX recently sent me some 40 meter crystals for use with my ET-2 transceiver.  Walter suggested that I use them to check into the daily (1300Z) Sunrise Net on 7123 kHz.  These were modern "short" computer crystals.  So I put them into FT-243 and FT-241 holders.  (Don't worry Greg, no WWII gear was destroyed in the process).  It was kind of fun to put the new rocks in old boxes. They work just fine in the ET-2.  Thanks again Walter! 



Finally, Chris KD4PBJ has been helping a buddy of his buy a Drake 2B.   This morning Chris asked about the E Crystal adjustment coil on the back of the Drake.  I told him that was to allow the use of "overtone" crystals.  But, sadly, I advised him not to worry about it too much because the days of ordering bespoke crystals (overtone or otherwise) are behind us. 

Tuesday, December 3, 2019

ET-2 Contact #18 W4FOA -- RANDOM, UNSCHEDULED, AND NOT SPOTTED (Video)



On December 1, 2019,  my 100 milliwatt signal flew more than 500 miles to reach Tony W4FOA in Chickamauga, Georgia. And -- icing on the cake -- this was a random contact.   Tony just heard my CQ on 7038 kHz -- he had not been alerted to my CQ by any spotting site or by the SKCC Sked page.  I made a quick video of my side of the contact (above). 

In a follow-up e-mail Tony explained how my CQ sounded to him: 


"I was just listening on the 40 meter band and having been a QRP'er for 50+ years, I tend to notice the weaker stations, thus explains my calling you.  Also, your signal had that little "sound" of "yesteryear" when signals were not all pure, hi.  Had it not been for the QSB and QRN we could have had a long chat despite the weak signal from your QRPp.  Over the years I have QRP DXCC, 2 way QRPARCI WAS, and my best DX was two QSO's with 2 different VK7 stations on 40 when I was running 1 watt.  I've had a lot of different QRP rigs and still have some home brew stuff plus a couple of HW8s, HW9, Elecraft K2, etc..."  

From Tony's QRZ.com page, we learn more about his ham radio activities (note his homebrew rigs and his obvious affection for the Drake 2B and 2BQ) 

First licensed as WN4FOA in April 1954. Other calls held include EL2AD, 7Q7AA, PY1ZBA. Prefer to work CW but I do work some SSB, primarily DX-related. Enjoy chasing DX on all HF bands. Have 9BDXCC and I now have worked and confirmed all of the current DXCC countries . I enjoy QRP operation and currently use an Elecraft K2 (#2213),Ameco AC-1, Kenwood TS-130V SW-40, DC-40, HW-8 (2), Heathkit HW-9 Deluxe (WARC) PSA-9 HFT-9B SP-99 HM-9 HD-420 VLF, MFJ 40T and MFJ 40V VFO,  and a homebrew 6AG7/6L6 or a 6C4/5763  etc. I also enjoy operating boatanchor gear which includes a Johnson Viking Adventurer, Viking Challenger,  an Eico 720 and an Eico 723 with a HG-10B VFO and a Heath AT-1 and a Drake 2NT. Recently added a neat Lysco 600 transmitter and a Knight Kit T-60, Johnson Viking II, and a Ten Tec 544.  Boatanchor receivers include a Hallicrafters SX-100, SX-110, SX-71, Drake R4C and the incredible Drake 2B/2BQ combo. Recently added a Kenwood TS-830S, VFO-240, AT-230 and SP-230.


Tony W4FOA
Thanks a lot Tony.  73

Sunday, April 21, 2019

A Beautiful Variable Capacitor (from Pete)


Is this a thing of beauty, or what?   Pete sent this to me back when I was having trouble finding a "smooth running" variable cap for my HRO dial receiver.  It has a standard Jackson Brother's reduction drive attached to the shaft, followed by a really cool gear arrangement.  Note the spring loaded teeth on the big gear -- that is to keep the gears tight when turning in both directions.  

As was the case with the HRO dial that Armand sent me, the beauty of this part will cause me to build something with it, really just for the purpose of putting it to use. We've been talking about double or triple conversion superhets with 100 or 50 kHz final IFs.  At those frequencies you can get good selectivity with LC filters.  As with the Drake 2-B.    Steve N8NM is sending me a dial that will go well with this part.  That will add to the already abundant mojo/juju.  I feel a VFO in the works.    Thanks to Pete for being so supportive of my luddite analogism.  

Monday, January 28, 2019

HT-37/2B QSO with K6ZA (three short videos)



On January 23, 2019 on 20 meters I talked to Barry K6ZA.  He is near San Francisco.  I was running my Hallicrafters HT-37 with my Drake 2B.  I was really pleased to discover that the guy I was talking to loves these two pieces of gear as much as I do.  

Barry said he wished I could record his voice coming out of the HT-37.   My iPhone came to the rescue.  




Sunday, January 13, 2019

SolderSmoke Podcast #209 SKN, Old Rigs, Movie Review, Safety Tips, Mail Bag


SolderSmoke Podcast #209 is Available: 

13 January 2019

http://soldersmoke.com/soldersmoke209.mp3

An HT-37 "With Presence!"  Even on CW!  A Straight Key Night Story
Saving a much-loved HT-37 
Drake 2-B Alignment
Tweaking the Mate for the Mighty Midget
Fixing a Deaf DC Receiver
A Wobbly National HRO-ish Gear Box 
Minimum Discernible Signal Tests
Pete's Festive Holiday Transceiver in a Bottle

Movie Review:  "First Man"  Neil Armstrong goes to the moon. 

Safety Tips for 2019:  Fuses, Hard Drives, Flu Shots. 

MAILBAG: 
Dave G6AJW builds Pete's Sudden Transceiver
Rogier KJ6ETL builds a new shack
Steve N8NM Helps save the HT-37
Jim AL7RV W8NSA builds Parasets
Dave AA7EE puts a beacon on the air -- Please Listen! 
Jan OM2ATC builds and documents an Si5351 VFO
Bruce KC1FSZ Homebrew's a BITX
KB1GMX's Tip on IRF-510 Oscillation Prevention
Ryan W7RLF Homebrews a DC Receiver

Listening to August K5HCT from the East and West Coasts on 40
Tim WA1HLR rebuilding his 1968 transmitter.  



Tuesday, January 8, 2019

Old Station On-The-Air -- A Transmitter Half as Old as Radio Itself

I'm biased, but I think it is "a thing of beauty."   With some unexpected free time available, today I followed up on my HT-37 work by cleaning and aligning the Drake 2B.  I was assisted in this by one of the many great YouTube videos by Alan Wolke W2AEW.   

The Drake 2B's 50 kc and 405 kc oscillators were right were they were supposed to be -- no adjustment required.  And I don't think they have been peaked since 1973.  The 455 kc IF can was also very close to perfectly tuned. 

Since most stations from the mid-1960s had some QSL cards on the wall behind the rig, I pulled out some old ones and put them up.  Many of these contacts were made by the rigs in the picture. 

If we say that 1897 marked the first use of radio, and if we assume that this HT-37 was manufactured in 1959,  that means that my old transmitter has been in operation for almost HALF of the history of radio.  

Friday, April 29, 2016

Reduction Redux: Searching for Some Smooth Spin

OK, here is yet another picture of my Mighty Midget's Mate receiver, this time with yet another main tuning dial. I gave up on the large reduction drive on the right -- it worked fine but was very stiff.  I cracked open a smaller version of this very common Japanese-made reduction drive, but in this smaller one I was kind of surprised to find  a Jackson Brothers drive in there.   I now had three of these beauties available -- all of them worked fine but with considerable difference in ease of turning.  I picked the one that was easiest to turn.  

I had to cut the main shaft of the beautiful Hammarlund 35 pf variable cap that I am using. This was dangerous, because of the risk of messing up the delicate bearings.   I stayed out of trouble by putting the tip of the shaft in a vise and then cutting the shaft with a small coping saw.  This prevented any force from being transferred to the bearings.  It worked. 

I was careful to try to line up the shaft and the reduction drive as closely as I could. 

I needed something to serve as the tuning indicator.  I used one of those small CDs that often carry the drivers for cheap electronic devices.  It fit nicely.  A standard sized CD was too big. 

The final element was the knob itself.  I had an old Drake 2-B knob in my junk box (who sent me that?).  It was perfect and added a nice touch of soul to this old-new machine.

I built this receiver in 1998 and when I finished it I thought it was pretty good.  But it is much better now.  It has a nice 455 kc Toyo Crystal-Mechanical filter.  The tuning ranges on 40 and 75 now line up perfectly with the phone bands.  It now has a fuse in the power supply. And the tuning is now SMOOTH.

   

Thursday, December 10, 2015

YS1RS's Salvadoran Tuna Tin and Drake 2B

Roberto YS1RS recently acquired a Drake 2-B and has some minor tech troubles.   I am sure Alan Wolke will come up with the proper diagnosis. (The receiver works fine on the standard bands, but not on the accessory bands.  He can hear the crystal oscillator working fine on the crystal frequencies, but the radio is for some reason deaf on all the accessory bands.)  

Above you can see Roberto's Salvadoran Tuna Tin. 

 Roberto Describes it: "Homebrew: The Tuna Tin 2 QRPp Transmitter (TT2) with 300 mW output power, 14.060 MHz (20 meters band), Crystal controlled, 13 Volts, CW-Only. As its name implies, its main chassis is a Tuna Tin Can.  In our case, it is a delicious and exotic Salvadorian made tuna in chunks, topped with Jalapeño Chile. "

Check out Roberto's QRZ.com page:

Roberto has an amazing collection of gear, much of it thermatron, some of it homebrew.  And he has only been on the air five years.  He is a true member of the International Brotherhood of Electronic Wizards.  His work takes him to some of the most difficult places in the world.  FB Roberto! 




Saturday, December 5, 2015

Alan W2AEW Hears me on 40 AM with his Drake 2B




Alan W2AEW writes: 

How appropriate! I was casually listening to 40m AM on my refurbished Drake 2B, and I hear the rotation get passed along to none-other than N2CQR - the man that got me excited about the 2B in the first place. FB 20 over signal in NJ, OM! I was able to grab the video camera quickly before you signed off.  Alan's video appears above.

73,
Alan W2AEW
Holy cow Alan,  THE RADIO GODS HAVE SPOKEN!  Clearly you need to get on 40 meter AM.  Maybe get a DX-60 or something.   In your video I spotted several items in your shack that are also in mine:  in addition to the 2B, I see  a Turner +2 transistorized microphone, and that little (very useful) RadioShack speaker. Glad you heard me OM -- thanks for the recording!
73 Bill

Saturday, October 17, 2015

SolderSmoke Podcast #181 Of Dongles and DX-100s -- SDR vs. HDR, Music & Art, 2B, HB2HB, Noise, The Martian, VK3YE's New Book



Two RTL SDR Dongles in front of a DX-100 Transmitter

SolderSmoke Podcast #181 is available:


17 October 2015

-- Our audience IGNORES Pete's guitar intro!
-- Pete on QSO Today Podcast.
-- Part 97, The Radio Art and International Goodwill.
BENCH REPORTS:
-- Pete connects his new beam to the KX3.
-- Pete puts the Bell-thorn on 20.
-- Simple-ceiver update.
-- Pete's new drum machine: http://makezine.com/2015/10/15/learn-electronics-worlds-oldest-drum-machine/
-- Bill fights noise in the DIGI-TIA.
-- Bill fights power-line noise (and wins!).
-- Drake 2B, skirts, reduction drives, and tuning rates.
-- Warming up (with!) the DX-100.

-- N2CQR -- N6QW  First Ever HB2HB QSO.

-- On 40 AM with an HT-37
-- Listening to Chinese CubeSats.
-- SDR Dongle as a bandwidth checker.

-- SDR and the Future of Homebrew Radio.

-- Bryan's LBS Receiver.
-- Dean's First Ever QSO with his HB rig.

-- 32 Mighty Mites Completed

-- The Martian -- Did Mark Watney REALLY have the Knack?

-- MAILBAG:
Peter Parker's New Book
Sparks from Ron Sparks
Armand's 1Watter
Rogier's  pyro machine
BIG boxes from Tim KI6BGE
Mikele's ZIA and N6QW rig collection
SPRAT 141 and SPRAT 164

Saturday, September 19, 2015

SolderSmoke Podcast #180 Pete's Beam, Simple-ceiver, 2-B, Noodling, Homebrew and SDR?, "The Martian", Mailbag


SolderSmoke Podcast #180 is available:

http://soldersmoke.com/soldersmoke180.mp3

19 September 2015

PROJECT REPORT:
Pete's Antenna Project:  The Joy of Rotation!
Simple-ceiver
Bill fixes Digi-Tia (after breaking it)
Shack Configured for Winter (DX-100)
Working (a little) on the Drake 2-B

SolderSmoke words we forgot to mention:
Noodling
The Radio Gods
The Radio Art
The Grand Poobah
Magic Smoke
Lud(d)ite Curmudgeonism

SDR and the Homebrewer

"QSO Today" Interviews
Lady Ada interviews Paul Horowitz of "Art of Electronics"

SHAMELESS COMMERCE:  Book still free!
Start your Amazon purchases at our blog page.

Book Review:  "The Martian"

Great QSOs with W5NDS and AE5RM

MAILBAG

Tuesday, September 15, 2015

Alan Re-Caps His Drake 2-B



That Drake 2-B is a beautiful thing.   Every time I look at an older tube rig I'm reminded of the three dimensionality of these old machines.   Solid-state rigs are in Flatland, but tube rigs are in three dimensions.

Alan makes a very cool use of the I-pad in this repair.  And I'm jealous of his Hayseed Hamfest Electrolytic (I opted for the multiple caps hanging below the chassis).  Excellent management of the solder-sucker by Alan.  And I was impressed by the disciplined way he pulls solder from the reel -- he has the reel right next tot he rig and dispenses it directly.  I tend to hack off small lengths of solder and end up with lots of little bits of solder on the bench. 

Glad to hear that the other caps on the Drake are standing the test of time.  I wish the same could be said for all the caps in my Heath HW-101.

One thing caught my eye in Alan's video:  The dial cord.   You know you have become a true 2-B aficionado when you have actually gotten good at replacing the dial cord.  It is something of a rite of passage.   Perhaps this will serve as the basis for a future video by W2AEW,

Thanks Alan!  And congrats on passing 4 MILLION YouTube views.  People watch because your videos are so good.   

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Saturday, September 5, 2015

Alan Wolke's Drake 2-B (video)



Alan's video inspired me to do a little work with my Drake 2-B.  Nothing major -- I was just making sure that the passband knob is in the right setting.  I've complained that the Drake 2-B doesn't sound great on AM.  I recently noticed that my BITX40 DIGI-TIA sounds surprisingly good with AM signals -- I just treat them as SSB signals and zero-beat the carrier with my Si5351 VFO.  I wanted to try doing the same thing with the 2-B, and then make some comparisons.  I only heard a few AM signals this morning, so I will try again later today and will report results here.   

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Sunday, May 3, 2015

Drake Dongle Derring-Do -- 2B goes SDR (video)



Here I take my Drake 2B  -- arguably the quintessential Hardware Defined Radio -- and connect its first Intermediate Frequency circuitry to an RTL-SDR Dongle, allowing me to digitally process, filter, and display (panoramically!) the signals being inhaled by the ancient receiver.  Another cool tech twist:   To get at the 455 kHz IF signal I use the "Q-Multiplier" jack on the back of the receiver.  This connector was put there to allow for the use of a selectivity enhancing regenerative stage.  So I'm using that connector for a similar purpose, but using technology that wasn't even being dreamed about when that Drake 2-B was being designed in 1961.  


Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Thursday, February 26, 2015

Video on W4OP's Progressive Receiver (Solid State Drake 2-B)



This is so great.  I saw pictures of Dale's receiver a few years ago, but somehow missed the video.   I am the proud owner of a W4OP-built Barebones Superhet.  And, of course, of a Drake 2B (mine has tubes!) 

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Sunday, October 12, 2014

Drake-uino! Arduino DDS puts Drake 2B on 12 meter band!



After using the Arduino DDS as a crystal substitute with my 1982 Barebones Superhet recevier (scroll down), I moved back two more decades and used the DDS as a crystal substitute to put my (early '60s) Drake 2B on the 12 meter band.    This was a hack in which I actually used a hack saw -- I used it to cut open the container holding a crystal so that I could make a socket that would carry the signal from the Arduino DDS into the Drake 2B. 

This video is a bit repetitive, but it stated out at two different videos.  I just put them together.  The last part shows the actual crystal socket hack. 

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Wednesday, May 21, 2014

Overheard at Dayton: Drake 2B Market Manipulation! (& Help needed with 455 kc IF can)


I received a very nice message from Preston Douglas.   Conveniently, he is an attorney, and I have asked him to stand ready to defend me in court should I ever be accused of manipulating the markets for Drake 2-Bs (and perhaps the market for SSDRAs). 

Can any out there help Preston with his SX-110 455 kc IF can?
 
May 20 at 3:38 PM
Hi Bill,
 
I enjoyed #160, even though I heard those talks, live at FDIM. 
I thought you'd be amused by what I overheard in the flea market on Saturday in Dayton.  I was looking at a Drake 2B and Q multiplier being offered by a lady who said they were her father's.  They looked to be in pretty clean shape, though of course there was no way to know what was going on under the hood.  She was asking $200 for both, and said she was open to reasonable offers.  Now, I already have a 2B and haven't found any need for the Q multiplier.  And I had flown out to Dayton from NY, so would have had to ship the pair of boxes home--probably should have bought them anyway and sent them home by UPS for that kind of money.  
 
Anyway, there were two other guys looking at the 2B.  One said to the other that these were among the best receivers of the tube era, but that the prices had become inflated by this guy who does the Soldersmoke podcasts talking up the virtues of the 2B.  Couldn't help smiling at that.
 
As to the Hallicrafters SX-110 on the repair bench.  Well, I worked out a deal with a professional tech guy to trade him my non-working HP 8640b sig gen for some bench time on the 110.  He found that the first IF  transformer that I was having so much trouble aligning was non-working.  He had no replacement, so he bypassed the whole transformer with a cap to get signal to the next stage.  This is, of course, not a satisfactory solution.  And nobody has that IF can to sell.  I did read on another radio repair guy's web site  that he, too, usually stops working on a set with a bad IF can because repair is so labor intensive.  
Frankly, I don't accept that.  I mean what's inside there?  A couple of coils and some open silvered mica leafs. So, I plan to remove the can, open it, and fix it.  According to the Internet, the built-in caps on these cans become defective and need replacement by modern capacitors.  Or, maybe a wire is broken off.  Before I do anything, I am going to see if that transformer is really unable to peak at 455.  Anyway, maybe I'll get some time to mess with this radio over the holiday weekend.  
 
One of the guys (or was it you?) recently said he builds 'em, makes a few contacts to prove they work, and then puts them on a shelf.  Then he builds another one.  It's like that sometimes.
 
PRESTON DOUGLAS

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Wednesday, January 1, 2014

Happy New Year! Straight Key Night

 
For the first time in years I got on the air on New Year's eve.  I fired up the HT-37 and Drake 2-B on 20 meters last night right at 0001 UTC  (well, with these rigs I should say GMT!).  There was a moment of stress when, as I was trying to adjust the key, the whole thing fell apart and the little ball bearings spilled out.  Yikes!  It was as if the radio gods were trying to tell me something.  It took me a few minutes to re-assemble my straight key, then I called CQ.  The HT-37 puts out a lot more power than I normally emit,  and it caused the Carbon Monoxide detector to go off, sparking a minor panic among family members.  (See, this never happens with QRP!)  With that resolved I had nice QSOs with K5KFK in Texas, W6VNR in California, and N1WPU in Maine.  This morning I worked WA0ZDE in Missouri.  The old HT-37 was drifting a bit, but Rick said he kind of liked that.  (I put a muffin fan on top of the transmitter -- that should settle it down a bit).   By the way, my key is a bit unusual: it is just a cheapo key, but I have it mounted on the base from a Vibroplex bug.  I never mastered the Vibroplex, and ended up giving the bug parts to HI8G in Santo Domingo -- Gustavo planned on using them to fix another bug that had been given to him years before by Fred Laun (K3ZO). 
 
Rick, WA0ZDE ( who I talked to on 20 this morning) sent me a VERY SKN photo collage (see below).  I see that Rick also tends to hold onto his gear for a long time. 
 
HNY to all!   GL in 14.  73! 
 



Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Thursday, December 5, 2013

W4OP -- Earth-Moon-Earth and Another Barebones Superhet


Years ago I bought a Barebones Superhet from Dale Parfitt on E-bay.  Several years after that, having forgotten who I bought it from, I was asking questions about how to get it working on 17 meters.  Dale jumped in with some very helpful e-mails.  It took us both a while to realize that I was working on the receiver that he had built.  Dale is active in a really wide range of ham radio activities, everything from QRP to EME.  Check out his homebrew projects here (I really like his Solid State Drake 2-B!) http://www.parelectronics.com/par-homebrew-projects.php 
And his vintage projects here: http://www.parelectronics.com/vintage-radio-restoration.php
And here's what Dale has been doing with the Moon (that's his 15 foot dish in the picture): 
 
Hi Bill,
 
I thought of you today when I won a Bare Bones Barbados RX on eBay for $5. I am going to team it with a DDS VFO and a matching TX.Some parts are apparently missing, but i have a huge junk box and also know how to order from Mouser should the junk box fail me.
 
 
Right now I am putting my solid state 650W 1296MHz EME amp , Power Supply, meters etc. in its waterproof cabinet so I can mount it right at the dish and not incur any feedline losses.
 
1296 is probably the best EME band. Power is getting easier and easier to acquire (although solid state is around $5/watt), dishes are fairly easy to acquire or build and  perhaps most importantly, we all use circular polarity feeds with no relays/hybrids. Activity weekend can sound like 20M, with a number of stations just ragchewing on CW and SSB.
 
73,
Dale W4OP
for PAR Electronics, Inc.
http://www.parelectronics.com


Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Wednesday, July 31, 2013

Soul in an Old Telescope


I like this telescope.  The owner built it in 7th grade and is still using it at age 70.  I'm still using the Drake 2-B that I bought with newspaper route money, so understand the sentiments.  

http://makezine.com/2013/07/29/through-a-diy-telescope-brightly/ 

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column