Hammarlund HQ-100 HQ-110 HQ-145 HQ-170 IF Repair

Hammarlund IF Repair. HQ-100, HQ-110, HQ-145 and HQ-170 IF transformers that have mica leaf capacitors in the base. How to remove them and reassemble.

[@ianbutler1983]

Charles, Thanks for showing your very clever repair. You explanation was clear, and even better, your closeup photography amazing. I know how difficult it is to do delicate work while filming it.

[@thespiritof76..]

I I only thought I knew how to work smart.... It’s gonna take me a few more years to catch up with this gentleman. Great instruction

[@frankkoslowski6917]

Excellent Camera management.

[@daleburrell6273]

Frank Koslowski ABSOLUTELY!!!

[@bobkozlarekwa2sqq59]

Your video just made what I thought was impossible, seem very doable! Thanks

[@JohnnyUmphress]

Excellent detail. This video really helps. Thanks

[@glasstronic]

Love your tool fabrication. Thanks for posting.

[@c60605]

Had no problems with the IF on my HQ-100, but while tuning the front end up the coil can L1 coil(s) came loose and became disconnected. Had to tear down, glue the coil form, and resolder the coils back and methodically reassemble it. Worked like a champ but the second band (1.6 - 4 meg) wouldnt tune flat, would regenerate and finally oscillate around 2.6 megs. I found a bad silver mica 100pf (C17) that was open! Replaced that, over all everything works fine, but still need to replace the rf gain control, someone before me put in an audio taper instead of linear, and have no real precise control of that cathode biasing. Nice radio overall!

[@DavidRitchie_n4djs]

at 10:34 it appears that there was still a piece of mica in the bottom.

[@jimw7ry]

The internal mica caps must have had mica cap "disease" ?

[@kennynvake4hve584]

I broke my cores yesterday on the 3 IF cans on my BUSH TR82D, which I got last week...It really pi............me off when it happened...it doesn't give a warning at all it just breaks...and since this radio was made only in the UK parts are very hard to get. Question..if I have another 455 khz IF can, are they interchangeable if the caps are the right size????

[@wolfhawg]

Which winding is the primary? The top or the bottom one.

[@daleburrell6273]

5:47...I'd use a jeweler's saw, or a razor saw for that operation.

[@DandyDon1]

It has been mentioned on the Antique Radio Forum that the early version Hammarlund receivers had this problem but not in later production. www.antiqueradios.com/forums/viewtopic.php?f=5&t=330921

[@charlessmith833]

Out of the 30 Hammarlund HQ-100, 110, 145, 170 radios I have owned I did not have a single one that was completely free of the mica sandwiches. I believe if Hammarlund had continued to produce them they would have fixed all their mistakes. The later models as well as the -A types were much better units. They are still good working radios. I have solid stated all of the above mentioned models and eliminated all the problems associated with tubes. The last remaining problems cannot be changed such as the variable capacitor tuning, the temperature sensitive tank circuit capacitors and the wafer switches. The solid state info is available to anyone who wishes to contact me.

[@DandyDon1]

In a search for the Silver Mica disease problem, I again found this video. I'm considering the purchase of a HQ-180A as I've wanted one for a very long time. Charles Smith, thank you so much for this information and I hope you are still healthy and active in your electronics repair pursuits. This though is a PITA and requires much patience.😅😁

[@nor4277]

Doesn't anyone have any new old stock IF cans

[@wa4aos]

Hi Charles, Great video. I have a HQ 110 that works great up to about 14MHz then the sensitivity does a nose drive. I wonder if one of the cans in my unit may have bad mica caps. The band switch has been cleaned and I aligned the unit according to the manual but the problem persist. Any thoughts? 73, Glenn WA4AOS

[@charlessmith833]

You probably have a bad oscillator tube or mixer. The IF problem will result in low signal throughout or no signal at all. It is best to fix all the IF transformers anyway because they will give you a problem sooner or later if not already doing so.

[@daleburrell6273]

+Charles Smith I was reading an old radio repair book, and it mentioned that an oscillator tube can test "good" in a tube tester, but it might NOT oscillate over ALL the frequencies that it is supposed to...this is a particular problem with the "pentagrid converter" type tubes- that combine the oscillator and mixer in the same vacuum tube. With this kind of problem, it is best try substituting another tube.

[@chetpomeroy1399]

Those tiny copper wires are reminiscent of the litz wire wrapped around the coil forms for AM ferrite antennas. Those lugs appear to be made of the same ferrite material. It's interesting how you beveled the hole in the bottom of the IF transformer to accommodate the old brass rivet that you put back in and flared. It would be a bummer if you were to put that all together without ohming it out and then finding out belatedly that you broke one of those delicate wires! That was a pretty neat trick you showed us with the tiny pieces of sheet metal for releasing that stuck wrapping from the inside of the IF shell!

[@charlessmith833]

I think it is litz wire. I have broken the wire before and it is a pain to work with. You can destroy the IF coil if you are not extremely careful. Another thing I should mention is that sometimes you will encounter shorts across the mica leaf and it will bleed high voltage over to the grid of the next tube. When that happens the radio will sound very crappy and you may become confused about what is happening. That's another reason to go ahead and fix them anyway and eliminate any chance of failure caused by the micas. Never install the replacement caps inside the can. Always attach the new caps outside the can so you can easily change the cap and adjust its value if needed. There have been times that the original value needed to be tweaked to make the IF resonate away from the travel extreme of the core adjustment. I am using 50v or 100v miniature ceramic caps for replacements. Since they are across the coil the voltage should never be too much for them. I haven't had any failures yet.

[@daleburrell6273]

I think you mean "SLUGS"...

[@daleburrell6273]

+Charles Smith I only RECENTLY found out what was the idea behind "litz" wire- it was to improve high-frequency response by reducing "skin effect".

[@daleburrell6273]

That's called an EYELET...not a ferule.

[@charlessmith833]

That's FERRULE not FERULE. When I worked for Johnson Controls we used a a piece that is almost identical and it was called a ferrule. It was inserted into a plastic tube to keep it from collapsing when making a connector. A ferrule is generally used for strengthening a joint and an eyelet is generally used for fastening and leaving a through hole. The shapes are identical as purchased but may be applied differently. I guess it's up to the beholder as to which is the preferred term. I'm glad you took the time to watch the video. As for the jeweler's saw, I don't believe many people have one but if you do I'm sure it will work. There are two different thicknesses of the Dremmel cut off wheel. The thinner one works OK and leaves plenty of metal to bend over for securing the "eyelet". Thanks for the suggestion.