Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco 38-690 tweeter improvement
#6

How do you have the treble/bandwidth control set? You need wide bandwidth to get high frequencies.

What are you using for source material? If your listening to just AM broadcast stations the tweeters will not see much use because most AM broadcast stations these days have very limited frequency response. Their frequency response does not go much past 5 kHz. Back in the day AM broadcast stations went to 10 KHz or more. In the case of WLW in the late 50's and into the 60's 20+ KHz.

If you really want to hear what your 690 can do build a SSTran AM transmitter. http://www.sstran.com/index.html

I built one for my father and he has a 37-690. With good source material the tweeters are noticeable.

Keep in mind a paper tweeter will never perform like a horn, dome or ribbon tweeter as they will roll off big time on the top end. I would guess they are good to 10-15 kHz.

edit: Ron I missed your post as I was working on mine at the time. I agree the tweeters get kind of bright with the bandwidth set full wide on my fathers 37-690. Any chance of popping the tweeters by dropping the crossover point down to 4000 hz on Dave's 38-690?

Bill

It's not what you don't know that hurts you it's what you know that's not so.


Messages In This Thread
Re: Philco 38-690 tweeter improvement - by Syl - 07-25-2008, 11:16 AM
Re: Philco 38-690 tweeter improvement - by Syl - 07-25-2008, 09:19 PM
[No subject] - by Ron Ramirez - 07-25-2008, 10:39 PM
[No subject] - by wonderwrench - 07-25-2008, 10:52 PM
[No subject] - by Ron Ramirez - 07-25-2008, 11:49 PM
[No subject] - by Dave Slusarczyk - 07-25-2008, 11:53 PM
[No subject] - by wonderwrench - 07-26-2008, 12:06 AM
[No subject] - by Ron Ramirez - 07-26-2008, 12:06 AM
[No subject] - by Ron Ramirez - 07-26-2008, 12:13 AM
[No subject] - by Dave Slusarczyk - 07-26-2008, 12:59 AM
[No subject] - by BDM - 07-26-2008, 01:40 AM
[No subject] - by wonderwrench - 07-26-2008, 01:48 AM
[No subject] - by wonderwrench - 07-26-2008, 02:30 AM
[No subject] - by Syl - 07-26-2008, 09:33 AM
[No subject] - by Ron Ramirez - 07-26-2008, 10:20 AM
[No subject] - by Syl - 07-26-2008, 12:52 PM
[No subject] - by Dave Slusarczyk - 07-26-2008, 04:33 PM
[No subject] - by wonderwrench - 07-26-2008, 04:47 PM
[No subject] - by wonderwrench - 07-26-2008, 04:53 PM
[No subject] - by Ron Ramirez - 07-26-2008, 05:40 PM
[No subject] - by Syl - 07-26-2008, 05:51 PM
[No subject] - by Syl - 07-26-2008, 05:55 PM
[No subject] - by Dave Slusarczyk - 07-26-2008, 06:50 PM
[No subject] - by Syl - 07-26-2008, 08:17 PM
[No subject] - by Dave Slusarczyk - 07-26-2008, 10:26 PM
[No subject] - by Syl - 07-27-2008, 12:11 AM
[No subject] - by Dave Slusarczyk - 07-27-2008, 02:02 PM
[No subject] - by Terry Judkins - 07-27-2008, 06:59 PM
[No subject] - by wonderwrench - 07-27-2008, 07:11 PM
[No subject] - by Dave Slusarczyk - 07-27-2008, 07:53 PM
[No subject] - by wonderwrench - 07-27-2008, 10:00 PM
[No subject] - by Syl - 07-28-2008, 11:21 AM
[No subject] - by Dave Slusarczyk - 07-28-2008, 06:10 PM
[No subject] - by BDM - 07-28-2008, 06:17 PM
[No subject] - by Ron Ramirez - 07-28-2008, 06:59 PM
[No subject] - by Dave Slusarczyk - 07-28-2008, 07:12 PM
[No subject] - by Syl - 07-28-2008, 09:33 PM



Users browsing this thread: 7 Guest(s)
[-]
Recent Posts
6TPZ and 5TPO Radio Help
Thanks, will do.R3Sons — 01:25 PM
1930s Stewart-Warner Tombstone Radio need help identifying model number
UPDATE: I was able to pick up a signal generator on the cheap (amazingly enough) on feebay and I did an IF alignment fol...captainclock1988 — 09:53 AM
Philco 91 Schematic
Hi Rod, The resistor connects to pin 4 and the ungrounded side of block 9. From pin 9 of the RF tube to one side of ...dconant — 09:34 AM
Just got a 49-1613 need to know...everything!
I just found your post. I have this exact same model, and have had it since 1985 when I was 15 years old! I performed a ...MuzzcoVW — 09:11 AM
B&K 1077B no video
Hello Tim, I would if it's a leaky Capacitor So are all 3 of those B- voltages low then ? Sincerely Richardradiorich — 01:55 AM
B&K 1077B no video
I found a schematic and think I have the problem traced down to the minus power supply. I have very low voltages that go...TV MAN — 12:41 AM
RCA 15X
I'd try replacing the bulb first and if that doesn't do it, then change the 35Z5 and see if the problem goes away.NostalgiaRadioTime — 12:28 AM
B&K 1077B no video
Hello Tim, I have that exact unit in my shop too plus a Sencore unit there are times I like one or other !!. Sincerely...radiorich — 11:07 PM
RCA 15X
Everthing goes at once, maybe it's the cold weather, I have had 2 dial strings break and no my little RCA is having dial...Paul Philco322 — 10:26 PM
Philco 91 Schematic
Hi Dan, I can't explain this specific resistor but I have seen the use of a switch to apply B+ voltage to screen gri...RodB — 09:36 PM

[-]
Who's Online
There are currently no members online.

>