Question About the T-615


Gary DeBock
 

Hi Kirk,
 
The Sony SRF-T615 is extremely sensitive for its tiny size, which is probably the main reason for its almost cult-like popularity. There is no other Ultralight radio so small that is so amazingly sensitive. As you mentioned, it is also exceptional in its nulling ability, which no doubt helped Rob and Richard log hundreds of stations. Both John and I used the barefoot SRF-T615 to log many TP's at Grayland, for a DXing thrill unlike any other.
 
For urban areas, however, the SRF-T615 would probably not be a good choice. It has mediocre selectivity (especially in relation to the new PL-380), and also spurious and image reception issues. In urban areas with heavy RF pollution, a radio with great sensitivity really needs to be overload-resistant, and the SRF-T615 just doesn't make the grade in this aspect. My local pest KSUH-1450 spreads out from 1430-1510 kHz when the SRF-T615 points its way, and the transmitter is over three miles distant. Even though the radio is probably a shade more sensitive than the PL-380 on most AM frequencies, the highly selective PL-380 would have far fewer urban side effects, and limit local splatter as well as any Ultralight radio in existence.
 
Full details on the SRF-T615 are contained in the 2008 Ultralight Radio Spring Shootout article, which is posted at http://www.mediafire.com/?zijl1lqtznn . This was also the article, by the way, that sent the SRF-T615 price into the stratosphere, at least for North American purchasers :-)
 
73, Gary
 
      
 
In a message dated 2/12/2010 6:30:51 P.M. Pacific Standard Time, kirk74601@... writes:

 

Hi All,

I am wondering if any of you living in a metro area with high rf noise problems have ever used a T-615? If so, how is it for adjacent channel and image rejections? I'm seriously thinking of getting one. After all, Robert Ross and Richard Allen love theirs, but they live in low noise areas compared to the Houston area.
I'd also be interested in anything that you've hrd or know about the radio even if you don't own one. I've read what I can on it, and it sounds like a winner....but I'm still debating with myself between getting it or a PL-380. I know the T-615 is superior for its nulling capabilities, but the 380 has its strong points as well, so.....limbo here for the time being.
Thank you in advance for any feedback.

Kirk Allen
Pasadena, TX


Kirk <kirk74601@...>
 

Hi All,

I am wondering if any of you living in a metro area with high rf noise problems have ever used a T-615? If so, how is it for adjacent channel and image rejections? I'm seriously thinking of getting one. After all, Robert Ross and Richard Allen love theirs, but they live in low noise areas compared to the Houston area.
I'd also be interested in anything that you've hrd or know about the radio even if you don't own one. I've read what I can on it, and it sounds like a winner....but I'm still debating with myself between getting it or a PL-380. I know the T-615 is superior for its nulling capabilities, but the 380 has its strong points as well, so.....limbo here for the time being.
Thank you in advance for any feedback.

Kirk Allen
Pasadena, TX


lrdheat
 

If I remember the blogging on the T-615 correctly, it is hot on the lower half of the band. I believe that it's nulling was about as good as it gets...I think that it was noted, however, that local pests can cover adjacent frequencies.
 
Heatwave


--- On Fri, 2/12/10, Kirk wrote:

From: Kirk
Subject: [ultralightdx] Question About the T-615
To: ultralightdx@...
Date: Friday, February 12, 2010, 8:30 PM

 
Hi All,

I am wondering if any of you living in a metro area with high rf noise problems have ever used a T-615? If so, how is it for adjacent channel and image rejections? I'm seriously thinking of getting one. After all, Robert Ross and Richard Allen love theirs, but they live in low noise areas compared to the Houston area.
I'd also be interested in anything that you've hrd or know about the radio even if you don't own one. I've read what I can on it, and it sounds like a winner....but I'm still debating with myself between getting it or a PL-380. I know the T-615 is superior for its nulling capabilities, but the 380 has its strong points as well, so.....limbo here for the time being.
Thank you in advance for any feedback.

Kirk Allen
Pasadena, TX



Gil Stacy
 

Kirk,

I have two. It is my favorite radio mostly because of its size; I use it every morning and afternoon when I walk my Aussie. It is a little "wide" with my locals during the day, but at night when power is reduced, it handles them fine. It is not as bad as the M37 and not as good as the E100 when it comes to adjacent frequency rejection of locals. Can't say I've noticed images. Four of them would fit inside my PL-380.

73 Gil


dhsatyadhana <satya@...>
 

Hi Kirk:

It sounds like you've got quite a bit of feedback, but here's a couple other observations. One thing about the T615 is that it doesn't have the birdies that the PL-310/380 have, and for audio fidelity, it really is a treat. I got mine through a Taobao agent for about $100 delivered, which is quite a bit cheaper than the other outlets.

That said, a DXer will want the PL-380. Checking frequencies just now in and around my 50 kw locals here in the Seattle area, which are generally 10-15 miles away, tough signals on the Tecsun were not even on the T615 due to the wide filtering, and where the Tecsuns could get a real clean signal it was still peppered with buckshot on the T615. I like the 380 better than the 310 (less soft mute, somewhat better tuning action), although the 310 has an FM/SW antenna jack if you're into those bands. If AM is your focus, the 380 is the best so far IMHO, and can be much more easily stealth modified with good Litz wire. With both, a modest passive loop like the Terk Loop will generally reduce the birdies to nada.

Kevin S
Bainbridge Island, WA

--- In ultralightdx@..., "Kirk" <kirk74601@...> wrote:

Hi All,

I am wondering if any of you living in a metro area with high rf noise problems have ever used a T-615? If so, how is it for adjacent channel and image rejections? I'm seriously thinking of getting one. After all, Robert Ross and Richard Allen love theirs, but they live in low noise areas compared to the Houston area.
I'd also be interested in anything that you've hrd or know about the radio even if you don't own one. I've read what I can on it, and it sounds like a winner....but I'm still debating with myself between getting it or a PL-380. I know the T-615 is superior for its nulling capabilities, but the 380 has its strong points as well, so.....limbo here for the time being.
Thank you in advance for any feedback.

Kirk Allen
Pasadena, TX


Kirk <kirk74601@...>
 

Thanks, Kevin. I appreciate your feedback very much!
-Kirk-

--- In ultralightdx@..., "dhsatyadhana" <satya@...> wrote:

Hi Kirk:

It sounds like you've got quite a bit of feedback, but here's a couple other observations. One thing about the T615 is that it doesn't have the birdies that the PL-310/380 have, and for audio fidelity, it really is a treat. I got mine through a Taobao agent for about $100 delivered, which is quite a bit cheaper than the other outlets.

That said, a DXer will want the PL-380. Checking frequencies just now in and around my 50 kw locals here in the Seattle area, which are generally 10-15 miles away, tough signals on the Tecsun were not even on the T615 due to the wide filtering, and where the Tecsuns could get a real clean signal it was still peppered with buckshot on the T615. I like the 380 better than the 310 (less soft mute, somewhat better tuning action), although the 310 has an FM/SW antenna jack if you're into those bands. If AM is your focus, the 380 is the best so far IMHO, and can be much more easily stealth modified with good Litz wire. With both, a modest passive loop like the Terk Loop will generally reduce the birdies to nada.

Kevin S
Bainbridge Island, WA


--- In ultralightdx@..., "Kirk" <kirk74601@> wrote:

Hi All,

I am wondering if any of you living in a metro area with high rf noise problems have ever used a T-615? If so, how is it for adjacent channel and image rejections? I'm seriously thinking of getting one. After all, Robert Ross and Richard Allen love theirs, but they live in low noise areas compared to the Houston area.
I'd also be interested in anything that you've hrd or know about the radio even if you don't own one. I've read what I can on it, and it sounds like a winner....but I'm still debating with myself between getting it or a PL-380. I know the T-615 is superior for its nulling capabilities, but the 380 has its strong points as well, so.....limbo here for the time being.
Thank you in advance for any feedback.

Kirk Allen
Pasadena, TX