Tuesday, 15 November 2016

FT-847 repairs

FT-847


Sometime since I've written anything here, its not that I've been doing less on the radio front when the opportunity arises, Its just that I've not been as inclined to bother taking pictures then writing about it here.

Anyway sometime ago my FT-847 lost power on HF/Lower VHF, a tiny amount of RF was present (drive levels) finally upon investigation it was clear the Finals were out, and Torroids in the BPF were cooked well also.


One of either 2 things happened here, the famous 46 Mhz spurious emission cooked up the BPF upon amplification when operating on 70Mhz or I transmitted into the 6 meter antenna when I was on 4 meter or vice versa, I have no evidence of the later, but the FT-847 shares the same antenna socket for both the 6 and 4 meter bands.

Torroids, a Lovely shade of gray, one fell to powder upon removal, all 3 in that section of the BPF were replaced.

Next up the Finals.









All done, I used a slightly different material for the torroid replacement with better heat handling properties, other than that same RF wise.
New finals installed and the board ready to be reinstalled into the radio.
The cost of the new finals makes this a job you'd not want to be doing to often on a 15 year old radio, so I decided to take some precautions to prevent his happening again.





The SP2DMB supplied TX filter (circled) This should deal with the Spurious emission just below 46 Mhz.
http://www.sp2dmb.cba.pl/70e/FT847eng.pdf
I only installed the TX filter for various reasons.

Also visible in the picture is the G4FUF 4 Meter LNA daughterboard, which replaced an earlier 4 meter preamp effort.


When doing the solderwork on the finals I pondered how to split the 4 and 6 meter band antenna outputs, this was very simple to do, in the menu of the FT-847 the 6 meterband output can be selected between the HF socket and the dedicated 6 meter socket, as far as the FT-847 is concerned for the most part 4 and 6 are one big band so when you move the 6 meter band the the HF socket you move 4 also to it, so you can put a 50Mhz antenna on the HF socket and 70Mhz on the 50Mhz and change menu 28 each time you change bands, not ideal but better than screwing in and out PL259s eachtime.

I decided to disrupt this and split the outputs, so menu 28 does exactly what it says, it controls the output selection of the 50Mhz output leaving 70Mhz attached permanently to the 6 meter output.

I did this using a relay, and the old ALC power limiting transistor.

I can now have 50Mhz output on HF output and 70Mhz on the 50Mhz socket. or have them sharing the 50Mhz output as standard, the modification is easy to reverse.
Wire Menu 28 controls removed from socket.
Taken to a location at the front.
Orange Patchwire installed



 White wire is original menu 28 control, orange is a jumper back to the original socket, red is + for the relay and gray is the control logic, which comes into play when 70Mhz is switched in.
 Relay
Relay board eared onto the fan screw.

Control wire for relay from former ALC control Transistor.

I actually did this modification close to 1 year ago, and I can't imagine returning to the inconvenience of a shared 50/70Mhz antenna output again or fiddling with menu 28 each band change.



Monday, 18 November 2013

Junk shop find

Recently came across this unmarked key in a New Zealand junk shop at a price I could not refuse.


Not really sure about it's origins but it is well built key, If I had to guess I'd say perhaps a 60/70s Japanese marine key?

Sunday, 2 December 2012

Oops

It seems I achieved exactly what I wanted to avoid when I started this blog, another dead blog. I aim to remedy this situation and get back upto a post or two a month on whatever I'm currently playing with at that point in time.

Sunday, 18 September 2011

KW2000 and some BUgliness

Its been a while since I posted anything, I've not been doing much on the ham radio front, messing around with a old FT101B which is just about working now, few minor issues to resolve.

I also got my hands on a non running KW-2000E in good condition, I've just gotten motivated to start giving it a going over, Physically its in nice shape, I hope I can get it running!




British Collins


KW electronics was a British firm that existed in the 60s/70s owned by G8KW


On the British equipment theme next up is a Eddystone bug...... which actually looks like a bug of the beetle variety, pictured with a McElroy S-600 key, also an unusual looking bug, but a very pretty looking key.


Cover off the Eddystone


McElroy S600 on the Left and Eddystone S 689 on the Right.

Wednesday, 11 May 2011

Uniden 2830 VFO mod.

Recently I've become slightly frustrated by having to press the span button so often when adjusting frequency on the 2830, I'm not sure if its the Chipswitch mod with its 4th span position or just me getting old and lazy.

Anyway I recently had an idea, locate an encoder with a momentary push button function, 3 quid something later and I have something close enough to the original but with the push function.

Today I set to work, the plan was to connect the push button function of the new encoder to the span function of the radio, quite simple, after a quick mess about I got the encoder working as it should (ie changing the frequency correctly) and I'm in business.





The Encoder prepared, next time I'll mount it onto the original VFO pcb, this was the prototype :-)






The Encoder in its new home, also showing the position of the wires piggybacked onto the original SPAN wires.

video

Tuesday, 29 March 2011

Les Logan bugs


While not rare or that collectible these bugs are nice to use and rather interesting.

On the left a Les Logan reverse frame bug and on the right I assume it is a Les Logan due to the similarities in the hardware to the Reverse frame bug, its 2.5 inch wide Logans answer to the Blue Racer?

Thursday, 17 March 2011

Time flies

Its been sometime since I updated my blog, I must make more of an effort to share my ramblings with the world in future.

Heres a picture of two interesting Bugs from my collection





On the Left is a Vibroplex Model X, its one of the more unusual Vibroplex keys in that it uses the same contact for both the dots and the dashes, the label has gone from this bug unfortunately, other than that its in good unrestored condition.

It dates from 1910-1920


***UPDATE*** It has been suggested to me by some that this key is not a vibroplex X but infact a AtoZ Model X, this maybe the case, hardware like the binding post and shape of base are more akin to AtoZ products than Vibroplex.


The bug on the Right is Vibroplex clone in direct violation of the Vibroplex patents of the time, this bug is made by a firm called AtoZ electric novelty co. of Chicago and cheekily called "Improved Vibroplex"

Vibroplex soon took legal action against a number of patent violators and won, they then offered to licence the illegal bugs for, the owner paid a fee, and the original label was removed and replaced with a tag saying that licence had been paid.

Vibroplex had threatened to sue any railroads that allowed operators to use unlicenced bugs, so needless to say many operators paid the fee.

This key retains its original label its in fair condition and pinstriping is still present, this bug dates from around 1914.


Friday, 17 December 2010

Chipswitch IC

Recently I've obtained a Chipswitch IC over here in the states, its NOS and the price was good, I intend to install this into my Uniden 2830 with the main goal of getting it onto 12 meters as well as 10, the chip itself has a number of useful features which make it worth installing.

The chip is no longer in production sadly, so I'm rather pleased to have obtained one, I really don't know why I never got one back in the 90's.



Wednesday, 24 November 2010

Fox Tango One Oh One

I've had a hankering for a valved radio for a while now, I've been keeping my eye on various radios Kenwood hybrids, Yaesu rigs, KW-2000B etc, anyway this old radio presented itself at a good price physically it was in good condition, it was sold as spare/repair for 105 usd I thought why not?

On arrival I swapped out the HV caps before attempting to power it up, the item was as described no RX no TX, no glow from the valves, the 25/100kc marker was not creating a signal either.

Following on from the HV capacitors I changed all the electrolyte capacitors in the distribution board, this took the tube heaters back up, PROGRESS!

Next step was to get RX, this is where it got confusing for a moment, the radio is a early FT-101 pre 25k serial, but many of the boards were transplanted sometime ago to later boards, anyway to cut a long story short, I continued the theme of changing el. caps this time in the audio board, this took the radio back to life, both RX and TX are now going! so much for a winter project! 

So I'm rather pleased, finally a real radio on my desk here in Denver, I have a TS-480HX which is a great rig, but the 101 feels right, I had a 101Z and a 101B years ago the Z gave good service, the B was part of a trade.

Anyway I'll just need to realign the radio, and install WARC bands into it, the plan is to use the 11 meter position for 12 meters, the WVV xtal will be jumpered to 20/40 band selector for TX on 30 meters and the AUX band switch will be filled with a 17 meter xtal jumpered to the 15 meter tuning gear


Wednesday, 13 October 2010

Errr

Again a lack of updates, been busy working etc, and I never really had much to blog about on the ham front.

I recently obtained a 1919/20 Blue Racer unusually this key has a T bar damper and not the normal U damper found on most Blue Racers of this era, Its got a lovely feel to it also.

Whatelse ham radio wise? well a couple more bugs have been obtained, also ordered a new band module for my Elecraft K1 it currently has 40 and 30 meters, I've ordered 17 and 15 meters, but I may convert the 15 meter band to 12 meters during build (unsure) Also ordered up the internal battery kit for the K1

Plans are inhand to put up a website with my key collection at some stage soon.

Thursday, 5 August 2010

Bug *ered

Just going through some photos of bugs I own, and I came across this sorry state, I got it on ebay a few months back for peanuts, but its in pretty bad shape, and hardly worth the effort to restore it, none the less I will, but not to original spec. I intend to paint it British Racing Green, and lacquer the heck out of it, yes the main spring is bust, but it can be replaced.
Something for the winter.






1920 Vibroplex with T style damper


Recently won this bug on Ebay, one of my few rare wins of recent, the main spring in this bug has been messed up also and repaired badly, intention is to replace the main spring the paint work won't be touched!

Monday, 2 August 2010

FT-847 gets ears for 4 meters.

I decided to carry out the PA1O mod for 4 meters and also install the CT1FFU preamp board, The preamp board was a very easy install.

The PA1O mod was also pretty simple and very rewarding the power is up at 85 watts now from 15 or so, It did take a bit of rummaging through the radio to get to the board to carryout the modification, once you get to the board its a case of desoldering a capacitor and thats it.
well sort of if your 847 has some transistor for controlling the ALC level on 4 (as i understand) you'll need to cut a leg off from it, mine had this transistor.


The HF and 4/6 meter final board at the top of the picture
Digging!!


During the installation of the CT1FFU preamp.


The CT1FFU board installed, its in a far more accessible location than the Power modification, I opted to attach the red + to a track that was more accessable than the one suggested (its not attached in the photo yet).
GM0USI Alan who lives close by has a 847 with a different preamp board and a different power mod. the plan is to get the radios side by side at some point and compare.

Friday, 23 July 2010

Electro Voice 638 *FAIL*

Tonight was bored and tried to wire up a impedance transformer into an old Electro Voice 638 50K ohm hi-Z microphone, while I got it physically inside without having to damage anything, the dang thing just does not work so good on the air, need to investigate further!





Wednesday, 14 July 2010

Uniden 2830 repaired

Earlier on in the year I took my Uniden 2830 out and plugged it in, No audio, confirmed the audio ic was fine and the main IC was opening squelch etc etc changed a few capacitors in the audio section and nothing, anyway I got busy with other stuff and the 2830 was left, yesterday evening 10 meters opened up briefly with sporadic E propagation into Southern UK and North Europe, well this spurred me on and last night I revisited the circit diagram for the 2830, this morning I plonked it back down on the desk, replaced a capacitor that may have been holding the squelch, bang hey prestor the 2830 is working!
Looking forward to working a few Sp. Es on it.

I've had this radio since I was around 13 years old, so its nice to see the old girl going again.





A while back I obtained a Turner 22X microphone head casing, It had been painted badly, anyway it polished up good, but was still useless as it had no internals, So! today I put a Heil HC-5 microphone element into the old beast, and mated the head up with an Electro Voice PTT microphone stand.






Quite a productive day Ham radio wise :-)

Saturday, 10 July 2010

Oops

Seems I've let my blog die, well I've been off the air, busy with other stuff, good stuff coming soon............. !

Sunday, 25 April 2010

Made it home.

Well I got back across the pond with no drama, I must say the Airlines have done a good job of getting things moving again after the Volcanic ash issues, of course stopping ALL flights was bit of a knee jerk reaction anyway.



I took a couple of bugs back across with me :-)




A World war II era Blue racer deluxe with unchromed base (due to the ongoing war) and a TAC bug which I rather like, Apparently TAC was some company the famous TR McElroy had a interest in.
Bug feels nice, looks nice, and sits very well.

Wednesday, 21 April 2010

Back to Europe? maybe..

Tomorrow I'm due to fly back to UK then next week to Belgium for a Seafood show, however this is looking not so likely with this Airline nonsense, I decided to put the bits onto the Standard key for safe keeping and good order, here are a couple of pictures of the result, I've not polished the gear up yet.


Okay I had a huge dilemma regarding the pinstrips, to go with the placement I found under the green paint, or to go with the placement of the pinstrips normally found on Standard Radio keys that feature them.

In the end I decided to go with the placement normally found on these bugs, as the strips on mine might not have been original anyway, and I preferred the over all look of the strips further in.

Fred KT5X gave me the placement offset so I must thank him for that and all the input he has given me, highly appreciated!




Also a couple of pictures of the Lefty VP original that I got via ebay, it had its components mounted upside down to make it function Right handed and was a mess covered in some shitty blueish paint, I did not realise it was a Lefty, It had no plate but it appears to be pre 1940 most likely somewhere in the 30's.
I got it for parts, and the only reason I restored the base was as a test bed for the Standard key, I started the standard well before this, actually I think its good working with 2 keys, gives you something to do when the other is drying etc, I have no plans to restore it any further unless for some reason I run into components for it.



During removal of the awful paint.




After.

Tuesday, 20 April 2010

Thursday, 15 April 2010

Callsign issued

So this afternoon the FCC issued me with a General class callsign KDØLEJ.
It should do me okay till I sit the Extra class, Just paid a visit to 17 meter put out a few CQs but the band is not in great shape.

Wednesday, 14 April 2010

Well the Standard Radio key is shaping up nicely, the odd setback now and again but I hope it turns out good, pictures to follow.

I forgot to mention, But on the 10th of April I sat my US Ham ticket, Passed the Technican and the General and I'm now awaiting a US callsign, maybe try the Extra, It would need a bit of study however.

73's