I won a SP-400

[w1vtp]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180370297898&_trksid=p2761.l1259

After all these decades.  My Elmer had one and always wanted one.  Wish it a safe journey -- hope it doesn't have to survive a 6 foot drop test.  I'll be looking for advise about the panel -- looks like some of the paint has chipped off

Al

[WQ9E]

Al,

Congratulations on finding one that you wanted.

The front panel is engraved aluminum so refinishing is not so bad.  Lacquer stick (available from Antique Electronic and others) is the easiest way to fill in the engraving after painting.

The safety covers over the terminals for the power supply cable are often missing so check and think about making replacements if they are missing; especially if you have small children or pets.

The meters are a little difficult to find so I would suggest putting diodes across the meter terminals to reduce the chance of needing one in the future. 

With a good signal, the audio is excellent when you can open the variable selectivity up to its wide setting.

Rodger WQ9E

[Pete, WA2CWA]

In my quick wandering last year at Boxboro, I saw two of these out in the flea market and both with power supplies.

[W1RKW]

Congrats Al.  I have one of these too. It works but not well.  It's a future restoration project.

[w1vtp]

Thanks guys for the congrats. 

I had an SP-100 that I put a LOT of time in restoring.  Like an idiot, I gave it way (what was I thinking!!) The bugaboo for these receivers is the bandswitch.  Some sort of cam mechanism where circuit boards are slid in and out of circuits.  The bronze (or copper) fingers would become either relaxed or corroded and made especially higher bands  bit tricky -- what with all the birdies etc.

Yes, this kind of receiver certainly takes a lot of work.  Fortunately, the whole tuning section comes out and you can really get at the "guts" of the receiver.  First thing after the power supply is replacing all the wax filled caps with orange drops.  Wish me luck.  BTW - I like the idea of back to back diodes on the meter.

I don't know what the prices were on the Boxboro SP-400's were - I was there too.

Oh yeah, is all the lettering engraved?  If so, refinishing the front panel might be real easy - a little sand blasting and primer and then the right color of grey -- then the lacquer stick for the lettering.

Al

[WQ9E]

Al,

It is all engraved including the rather strange looking (to me anyway) script used for the Hammarlund logo.  Be careful with the bead blast (maybe nut shell blast?) since the panel is aluminum and the engraving isn't terribly deep.  You might need to clean out the engraving with a blunt instrument after painting the panel.

I vaguely recall reading a post or email where someone filled in the engraving with a soft material like white out prior to painting.  According to the poster it was then easy to clean out the engraving and refill with a proper material.  I have not tried this and cannot find the post but I may experiment on an NC-183 I need to respray.

Rodger WQ9E

[w1vtp]

Al,

SNIP 
  Be careful with the bead blast (maybe nut shell blast?) since the panel is aluminum and the engraving isn't terribly deep.  You might need to clean out the engraving with a blunt instrument after painting the panel.

snip

Rodger WQ9E

Excellent point.   I'll check around before I do something

Al

[WU2D]

Congrats Al,

I got one of these 5 years ago and have enjoyed bringing it back to life. I have lots of notes and a scrap book if you want to borrow some info. I built my supply.

Mine had no meter so I "made" one.

Mike WU2D

[w1vtp]

Congrats Al,

I got one of these 5 years ago and have enjoyed bringing it back to life. I have lots of notes and a scrap book if you want to borrow some info. I built my supply.

Mine had no meter so I "made" one.

Mike WU2D

Mike

I would be very interested in your notes.  Great that we are close to each other.  I'll get my 400 settled in and get in touch with you.  As noted before, I had a SP-100 and had pretty much recapped the thing (wax --> Orange drops).  What I didn't do was figure out to deal with the band switch.  I'd be interested in picking your brain on that score.

Nice pics BTW

Al

[steve_qix]

There is one great feature the SP-400 (and BC-1004/779, etc) has - and that is the continuously variable IF bandwidth.

I use a BC-1004 for my main station receiver - converted to solid state, but otherwise the IFs are all BC-1004 original.  I actually own 4 of these receivers (2 super pros and 2 BC-1004s).

The skirt selectivity is not good, so don't expect much on that score.  In its stock form, the audio is poor (some here will disagree, but I'm comparing the stock receiver's tube audio output to a homebrew 50 watt solid state amplifier - and as compared to that, the audio is VERY poor).

The detector is not bad... and if you take audio from across the audio gain pot and feed it to an external amplifier, it will be reasonable.  I seem to recall the AVC was usable, but its been a long time since I've used one in stock form!

Because the IF skirts are shallow, the frequency response (of the IF) is very good, and is pleasant to the ear.

Anyway, that's my $.02   

Regards,

Steve

[WU2D]

Al,

Don't let Steve near it - he will solid state it for sure...

Mike WU2D