Pages: 1 [2] 3   Go Down

Author Topic: VLF converters?  (Read 54160 times)

N4AEQ

  • Member
  • Posts: 107
RE: VLF converters?
« Reply #15 on: July 06, 2017, 02:15:48 PM »

 Just purchased on of these [ELF HF Upconverter for Measuring Technology HAM radio RTL SDR] $29.00 ebay, seller is janilab
I bought one of their HF upconverters years ago, works great for 160m and up so I am hoping this one will do as it says and
go from DC & up.  Should arrive in 2 weeks, will post a review then.
Logged

WA4JNX

  • Member
  • Posts: 26
RE: VLF converters?
« Reply #16 on: July 10, 2017, 02:37:44 PM »


http://www.ebay.com/itm/VLF-Converter-5kHz-to-500kHz-ready-built-made-in-Dorset-UK-/282537940958?hash=item41c892d7de:g:mEkAAOSwVJhZS21l

First Impressions of the new UK Ebay VLF converter:

1.They send this converter by Registered Mail.

Cost is $105.12 delivered...but you have to be home to sign for it.

2.Performance is no better than a Heathkit.The design and utterly complete shielding eliminates virtually

all MW feedthru but the low end (60 khz) and high end (515 khz) are mediocre at best.

WWVB is very weak as on the Heathkit...best freq. range is midband but that's where it's tuned (250 khz).

3.So in the final analysis you would be better off to go with Chuck Olsen's 14 buck Jackson Harbor Press kit.

4.But the 630m Special version of this converter would probably be fine,being tuned for 475 khz.


Logged

VA3VF

  • Member
  • Posts: 4509
RE: VLF converters?
« Reply #17 on: July 10, 2017, 02:49:52 PM »


First Impressions of the new UK Ebay VLF converter:

2.Performance is no better than a Heathkit.The design and utterly complete shielding eliminates virtually

all MW feedthru but the low end (60 khz) and high end (515 khz) are mediocre at best.

WWVB is very weak as on the Heathkit...best freq. range is midband but that's where it's tuned (250 khz).

3.So in the final analysis you would be better off to go with Chuck Olsen's 14 buck Jackson Harbor Press kit.


Thank you very much for the update.

Going through my old stuff, I found one of Chuck's LF converter kit, still in the plastic bag. It must be from around 10 years ago.

I think I'll stay with it for now.

73 de Vince, VA3VF
Logged

WA4JNX

  • Member
  • Posts: 26
RE: VLF converters?
« Reply #18 on: July 11, 2017, 05:17:58 AM »

Final thoughts re the ebay converter:

1.It did very poorly in last night's testing...
much MW feedthru and a lot of HF feedthru
(all converters do this on 4 mhz output but
this one does it quite well).
Not very sensitive at all.

2.Save your money...the Jackson Harbor Press
ran rings around it last night from one end of the
band to the other.

3.The pity is this unit has superb parts and workmanship
but when it only hears your local NDB (BH224 here)
that says it all.
Logged

K5TED

  • Member
  • Posts: 294
RE: VLF converters?
« Reply #19 on: July 16, 2017, 05:07:57 PM »

Mine shipped yesterday,$105.12 usd delivered.

This is the built and tuned version,10-500 khz.

He offers your choice of Antenna Input/
Converter Output connectors,RCA,BNC or
SO239,no extra charge.

Also a "630m Special" at no extra cost,tuned
at 475 khz for max gain.

And an ELF version,01.-100 khz.

All are available in kit form.

Will let you know how well it performs.


So? What happened?
Logged

WA4JNX

  • Member
  • Posts: 26
RE: VLF converters?
« Reply #20 on: July 30, 2017, 05:25:27 AM »

VLF Converters Update:
 
1.Art and Steve of Hamcrafters say a new version of their
Hamcrafters/Palomar converter will be out by late September.
The IC used is no longer available in DIP form so the board
is being changed to take the surface mount version.(Art
purchased the full rights from the late Jack Althouse of
Palomar in 2010).

2.Chuck Olsen of Jackson Harbor Press 14 buck converter
fame advises he now has plenty of DIP IC's for his
converter so it will be around for a long time to come.

3.Reportedly MFJ is working on their converter along
with some other things for 630m,for release in September.
Logged

N0YXB

  • Member
  • Posts: 1663
RE: VLF converters?
« Reply #21 on: July 30, 2017, 09:25:15 AM »

Awesome, thanks for the update.
Logged

K0OD

  • Member
  • Posts: 3039
RE: VLF converters?
« Reply #22 on: July 30, 2017, 09:38:27 AM »

3.Reportedly MFJ is working on their converter along
with some other things for 630m, for release in September.

That item deserves special mention.

Would be good to see the Palomar on the market again. It's a simple design, about 15 capacitors and 13 resistors. I'd like to see a new version with a trimmer for moving it on frequency for modern receivers and modes. Still mine was only about 300 Hz off! The Palomar was made in two versions: The VLF-A outputting to the 3.5 Mhz range, and the VLF-B for 4.0 Mhz.
Logged

K0OD

  • Member
  • Posts: 3039
RE: VLF converters?
« Reply #23 on: September 24, 2017, 01:48:55 PM »

VLF Converters Update:
 
1.Art and Steve of Hamcrafters say a new version of their
Hamcrafters/Palomar converter will be out by late September.
The IC used is no longer available in DIP form so the board
is being changed to take the surface mount version.(Art
purchased the full rights from the late Jack Althouse of
Palomar in 2010).

2.Chuck Olsen of Jackson Harbor Press 14 buck converter
fame advises he now has plenty of DIP IC's for his
converter so it will be around for a long time to come.

3.Reportedly MFJ is working on their converter along
with some other things for 630m,for release in September.

Just checked their websites and neither Hamcrafters nor MFJ show a new longwave converter yet.

Heros Technology of England has added more longwave info to their website including nice videos of their converter in use:  https://www.herostechnology.co.uk/pages/VLF-LF-MF_Up-Converter.html

Logged

KA4NMA

  • Member
  • Posts: 597
RE: VLF converters?
« Reply #24 on: September 24, 2017, 10:46:49 PM »

Just purchased on of these [ELF HF Upconverter for Measuring Technology HAM radio RTL SDR] $29.00 ebay, seller is janilab
I bought one of their HF upconverters years ago, works great for 160m and up so I am hoping this one will do as it says and
go from DC & up.  Should arrive in 2 weeks, will post a review then.

Links??

Randy Ka4nma
Logged

K0OD

  • Member
  • Posts: 3039
RE: VLF converters?
« Reply #25 on: September 25, 2017, 06:12:01 PM »

Try this:
http://www.ebay.ca/itm/ELF-HF-Upconverter-for-Measuring-Technology-HAM-radio-RTL-SDR-/282600625010?hash=item41cc4f5372:g:F8oAAOSwa~BYRnUL
Very confusing since the above is simply called "ELF HF Upconverter for Measuring Technology HAM radio RTL SDR."

There's also this very low frequency converter that seems to go by the catchy name of "Very Low Frequency Converter."
http://www.ebay.com/itm/VLF-Converter-5kHz-to-500kHz-ready-built-made-in-Dorset-UK-/282537940958?hash=item41c892d7de:g:mEkAAOSwVJhZS21l

Logged

WA4JNX

  • Member
  • Posts: 26
RE: VLF converters?
« Reply #26 on: July 26, 2018, 08:59:22 AM »

While talking to Steve at Hamcrafters about another matter,
asked about the status of their Hamcrafters/Palomar VLF Converter.

His reply:

I have an SMT redesign of the VLF converter finished and tested, it's the enclosure that is holding us back.
We were trying to come up with an enclosure design that would work for several products to save on design
and fab costs.
It's turned out to be an unreachable goal so we are going ahead with a
unique enclosure for each of three new products, one of them is the VLF.
It'll be ready in the Fall.

Steve
Logged

KM1H

  • Member
  • Posts: 11155
RE: VLF converters?
« Reply #27 on: July 31, 2018, 04:57:53 PM »

Dont all modern transceivers go down to at least 100 KHz on RX?  I use a TS-940 and 950SD for 630 and 2200 and a HRO-500 with LF-10 for down to 5 KHZ.

I wish the Chinese would come out with a decent $100 transverter for each band with a 10M IF to minimize feedthru.

Carl

Logged

VA3VF

  • Member
  • Posts: 4509
RE: VLF converters?
« Reply #28 on: July 31, 2018, 05:04:19 PM »

Quote
Dont all modern transceivers go down to at least 100 KHz on RX?  I use a TS-940 and 950SD for 630 and 2200 and a HRO-500 with LF-10 for down to 5 KHZ.

I don't know if all modern transceivers will go down there. But I think most of them are deaf, because of the attenuation introduced to block AM BCB.
Logged

K0OD

  • Member
  • Posts: 3039
RE: VLF converters?
« Reply #29 on: August 01, 2018, 07:09:33 AM »

I just did a quick survey of the advertised specs of ten current HF transceivers from five manufacturers and all claim to receive down to at least 130 kHz. Most are spec'd down to .030.  That doesn't mean all will perform well near strong  AM BCB stations.
Logged
Pages: 1 [2] 3   Go Up